Hello Skoran!
The first thing is caused by regional troop availability. If I am not mistaken you are also unable to recruit pezhetairoi in Ambrakia. Mostly regional troop availablity is important for Regional barracks, but can also occur with Factional barracks. Because I did not know that in my Epeiros campaign, I missed out on the hypaspistai and Peltastai Makedonike...
You should try to build as many factional barracks in your homelands, Ambrakia will give you elephants and the old Makedonian provinces give the elite infantry. Also, if you still have Taras and upgrade the barracks there, you will be able to recruit the regional Tarantoi Hippeis (Tarantine Elite cavalry) as Factional units (I hope you still understand what I mean, it is quite confusing).
I would advise to build a type 4 government in Tylis, so when you get the lvl 5 Regional barracks, the Regional Thraikioi Romphairaioi are becoming available, strong, armour wearing falx men, who will cut your enemies to shreds!
Hope this helps!
~Fluvius
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