Sloughis are registered and judged according to their looks alone, it does not matter where they come from
 Wrong
1) The imports are registered within the Fédération Cynologique Internationale (FCI) according to their countries of origin
The FCI's Sloughi standard states that the main country of origin of the Sloughi is Morocco and that this always short coated breed comes from North Africa. Dogs imported from Morocco, Algeria, Tunisia and Libya have been and still are registered with the FCI.
The FCI's Saluki standard states that this breed which exists in 2 types of coat, short or long-haired, comes from the Middle East..................... The Middle East is not North Africa. 

2) the countries of origin are crucial for indigenous breeds whether Sloughi, Saluki or other sighthound breeds. The Country of Origin and the Culture which bred these Sighthounds are what defines indigenous breeds.
The distance between these countries is of utmost importance because it gives an indication as to whether these populations were in contact with each other or not during their evolution and history. The greater the geographic distances, the less the dogs interbreed and the greater the chances of genetic isolation and resulting Genetic Drift which modifies the DNA over time. 
Examples: the distance between Rabat (Morocco) and Riyadh (Saudi Arabia) by flight is 5192.2 kms (3226.3 miles), between Rabat (Morocco) and Kabul (Afghanistan) by flight is 6777.9 kms (4211.6 miles) somewhat equivalent to the distance by flight between Paris (France) and New York (USA) of 5827.5 kms (3621 miles). These distances are much longer by road.

3) this argument implies that any lopeared short coated Sighthound showing up in rescue is a Sloughi. Looks can be very deceiving, there are many crossbreds which look superficially like Sloughis. Many Longdogs (crosses between Sighthounds) and Lurchers (crosses between Sighthounds and other breeds) which show up in rescue as "Sloughis" are good examples of how confusing it can be. 
Does that mean that such crossbreds should be registered with the FCI in the first generation?
No, because they do not come from North Africa, even if some have Sloughi blood, particularly in the United Kingdom where hunters have quickly realized the hunting talent of the Sloughi and blended the Sloughi DNA into their Longdogs and Lurchers.

Genetics are not important because before the field of Genetics was developed people bred on looks alone
Wrong, before the field of Genetics was developed people bred with local lines selected in a particular environment, in a particular cultural setting/society and for a specific function. These local lines of indigenous Sighthounds did not for the most part come into contact with large scale genetic exchanges with similar looking Sighthounds thousands of kms away. 
They did not breed with each other because they could not due to the distance, therefore they did not mix their DNA which evolved differently across centuries as a result of Genetic Drift.

It is only during the last century, because of  the ease and speed of travelling, that dog breeds from far away came into contact with each other.  This applies to all dog breeds, and it includes the Sloughi and the Saluki. The ease and speed of travelling is the most important danger to the preservation of local indigenous breeds.

In fact scientific studies on the Genetics of dog breeds show so far that Sloughis and Salukis do not have the same DNA. They have unique parts of their DNA equivalent to differences used to identify samples determining the outcome of criminal cases in the courts of Law.

Laba'an II al Khalij never produced long-haired puppies, so crossbreeding to him does not matter.
Wrong, that remains to be proven, as there is a written testimony saying that about 50% of the puppies were destroyed by the breeder at the time. 
Why were they destroyed one may ask?

A short coated Saluki does not have the DNA of a North African Sloughi.
Short coated Salukis can be either carrier for long hair (heterozygous, they have one allele instead of 2 of the gene for long hair)  or "clear" for long hair (homozygous for short hair, they have no alleles of the gene for long hair).
Two short coated Salukis carrier for long hair will produce litters of short coated and long haired Salukis, because the single allele of each parents will combine in some of the pups who will then have both alleles of the gene for long hair and therefore be longhaired (long hair is inherited recessively).

Being short haired does not make a Saluki a Sloughi. A short coated Saluki has the DNA of the Saluki, it has the same DNA as his feathered relatives except for the gene which produces long-hair, one gene out of roughly 20.000 genes.

Breeding Sloughis to Salukis or Afghan Hounds or Greyhounds or Whippets is creating mongrels out of formerly geographically distinct populations, it does not matter how pretty they are. 

Hunters in the UK and the USA want crossbreds to hunt, there is really no problem with that, but they have the decency of not messing up the Studbooks of these breeds by registering such mongrels as pure-breds of these breeds.

Sloughis in North Africa could be mongrels because most have no pedigrees, we should not breed with them.
Wrong, this is a colonial, arrogant and demeaning attitude towards the traditional breeders of Sloughis in North Africa. 
There are crossbreds in every country of the world so if there are mongrels in North Africa it is nothing special.
However, let us not forget that the North African Sloughis were bred and selected by traditional breeders over centuries in North Africa long before the creation of dog shows and registries. Traditional Sloughi breeders know the difference between a Sloughi and a dog which is not a Sloughi. 
It is from traditionally bred North African Sloughis that the "real" Sloughi bloodlines in the West descend from.

As seen with the scam of the Western registration of the Saluki Laba'an II al Khalij as a Sloughi, registries and their pedigrees are not always a guarantee of purity of breeding, and what is the point of a pedigree which shows dogs of other breeds?.

Although there is nothing wrong with presenting a Sloughi at a dog show, and with the pleasure of winning, the fact of the matter is that the Sloughis bred in North Africa are not bred to trott prettily around a show ring and bring back a ribbon to the owner. 
Their value resides in their selection by traditional breeders for their talent and courage in hunting and guarding, and the resulting good instincts, looks and structure. Few breeds still have access to the populations they originated from. The breed Sloughi is fortunate in that it still has populations bred traditionnally in North Africa which can be a repository of a rich gene pool. Serious Western breeders incorporate such bloodlines to prevent the disastrous consequences of inbreeding which plague the show dogs of many breeds in the West. 

Whether these Sloughis have Western style pedigrees is irrelevant. North African traditional breeders know their bloodlines, they are the ones who bred this breed for centuries. And a pedigree can be started within the FCI system for Sloughis imported from North African countries with no Western type Registration System.

My dog is a champion, it implies it is a Sloughi.
Wrong although the registration at the beginning of a registered bloodline, if the owner is honest, is made according to the country of origin, a judge can only evaluate the looks of a particular dog which has been registered with the FCI in the show ring. 
1) a judge cannot know the bloodlines and the mixes in the lineages of the dog he or she judges.
2) a judge can be knowledgeable or not knowledgeable about the North African Sloughi. A judge with little in depth knowledge of the breed will not recognize proper North African Sloughi type.
3) the crossbreds of Sloughi with Saluki blur the morphological differences between the breeds because they look somewhat "in between" these 2 breeds and make it difficult for a judge to recognize what they are. 

It does not matter anyway, Sloughi and Saluki are the same anyway
Wrong, that may be a personal opinion, not supported by the results of genetic studies, but within the Fédération Cynologique Internationale which includes Morocco, these breeds are recognized as distinct,  Sloughi and Saluki are different breeds.
So it logically and legally follows that one should not be able to register a Saluki as a Sloughi and a Sloughi as a Saluki and that the puppies of a Saluki with a Sloughia  (or vice versa) are mongrels and should never have been registered with the FCI.

If someone likes the look of crossbreds between these Sloughi and Saluki, there is no problem with that as long as they do not register them as pure bred Sloughis and thus mess up the integrity of the Sloughi Studbook and of the bloodlines with Saluki foreign genes which do not belong there.

In addition such crossbreds should NEVER be exported to North Africa and mess up the genome of the authentic traditionally bred Sloughi bloodlines there.