I know the Perry 'Armenians' castings quite well. I was rather disappointed with the single pose overarm spear position when I opened the box (bought sight unseen), compared to everything else in that range - even the Armenian bowmen.
In fact, I decided to do some arm position conversions - not something I'm particularly good at, or like doing. They look OK, at a pinch, and a bit different to how they came, but I'm not sure I fancy going through the process again. P.S. rebased them since this picture was taken.
As for Kurds, I'm not sure either, except that they are possibly a bit Persian looking. I suppose I should be glad that no one seems to know, perhaps, as you say, anything Arab looking will do.