first time a serious challenge - how to beat the romani? - (battle diff.: very hard)

[Ca Putt]

I'm no VH expert but from my experience AP weapons are the way to go against pedex romani.
that means for a hellen(ist)ic army:
replace lonchophoroi with hetairoi, Prodromoi, Tessalians or the like as they(LH) cannot play their advantages against romans(big shield, mediocre staying power)
generaly play a bit unrealistic in terms of army composition: more slinger(as mentioned) more cav less normal infantry(thus anythign that's neither a phalangite nor has a AP weapon) a unit of thorakitai or the like may be usefull to catch and kill the odd unit of roman cavalry but apart from that not the most usefull option against the romans.
phalangites are actually not too bad when fighting romans as they soak up a lot of the javelins damage. -> which makes it safer for your flanking troops

you could also mount some amphibious siege parties that distract the romans from the front, works every time ^^. tho that leads to romans spamming neitos and celtic levies^^

ps well getting the idea on your own is probably best :D(concerning opening a second front)