why is it so hard to get battle stars for my generals?

[Redmeth]

The Eleutheroi part is intended to stop AI steamrolling, the problem is that sometimes a faction gets lucky and gets a many-starred general(this is damaging in the early game mostly).
I saw an Epeiros general (the guy that starts in Taras) beat a lot of Romans and gaining many stars also with the help of the many mercs in southerm Italy (especially the very strong Saminticii Milites) he took out Rhegion (rebel city) and then methodically defeated the Romans until he took Arpi, Capua and Rome.

I mean he just obliterated some strong armies led by young generals or captains.

Granted. the Romans kept trying to take the strong Eleutheroi cities to the north and losing many men there (I agree with the strong Eleutheroi BTW)

EDIT: On second thought sometimes Hannibal happens, so to speak.