The sabyn look really interesting. I was going to play as them first actually, but in the last build they were a little skeletal. I love the idea of pre-islamic Arabia, although i know very little about it. Thanks for the advice, Errant, i do see how you could deploy medium infantry well. I guess its a matter of taste whether you want to invest in them when money is an issue (ie pre-REDICULOUSLY productive mines.) I myself tend to focus almost exclusively on shock and archer cav, with skirmishers and a few light infantry to fill in the gaps caused by money constraints. But as your conflicts start to become more intense it is important to invest in line infantry, especially for taking/defending cities. At this point, any Armenian general would thank the gods for native medium infantry.
I certainly dont think that Armenian infantry does or should suck. I think my original point may have been somewhat misunderstood. It was about the tiknapah, which seemed out of place by being difficult to get, but little different from sooseramartik. Partly i was a little perplexed by the lack of late game cataphracts, but i think these might have been added in the last build (if someone wouldnt mind confirming or denying this, i would appreciate it, by the way)
By the way i agree about javelin cav: too little ammo to be really useful.
In answer to the other question, my armies are usually smaller. The good thing about skirmisher cav armies is the way you can concentrate your forces at one point, thereby gaining effective superiority of forces even when your out numbered. Ususally i will string out one unit of phalangites with the majority of my army and focus on annihilating it with arrow-fire and then breaking it with a charge. When you run out of ammunition you just withdraw and then do it again. Of course with high end seleucid units you have to be more careful, but the same tactic essentially works.