Roman Palace

[Poulp']

you're talking about the hard coded marian reform, right ?
from what I recall, only Baktria and another faction I don't remember (not SPQR) benefit from it.

edit
excerpt from EB faq
https://forums.totalwar.org/vb/showthread.php?t=84854

Other Reforms:
All other factional reform units are tied to the "March or Time" event (Vanilla Marian Reform) which requires the Romans to build a huge city in central Italy to trigger. This is just an arbitrary time delay.

that's all there is about it in the faq
it's kind of frustating though because I know I'm overlooking something and I can't tell what it is.

By the way
it's fortunate I had a link to the FAQ because I couldn't find the thread manually.