Different skins on single-make grid ?

[Gaudin de Beaufort]

If I choose opponents with "single-make grid", I get all different skins for some cars and one and the same skin for other cars.
Why is this, and is there a way to always get different skins with a "single-make grid" ?

 

[PiotrGT]

It could be that some of those skins don't have number assigned. Try unchecking "Avoid cars without skin numbers". You can also disable "Pick skins sequentially" if you wish to have more randomized AI skins as well.

 

[Gaudin de Beaufort]

Many thanks for your reply !!!