Originally Posted by
BailianSteel
Sounds good!
The thing is that the backing of the various Basileu and the loyalties of Poleis has traditionally been fickle. If the Romani move to attack Epeiros itself Pyrrhos will definitely prioritize defending it. If he loses Epeiros then he'll essentially be dependent on the good graces of the Poleis and his rivals, both of which have historically proven to be wanting. However, given how unstable the situation in Hellas was at the time, he might be able to drive Gonatas out of Thessalia before the Romani can arrive, especially with how the Keltoi and Qarthadastim are bearing down on Italy. That should give him and KH breathing room to defend Epeiros.
With the combined resources of Pyrrhos and Koinon Hellenon, plus funding from Qarthadast and Aigyptos, I don't think Gonatas will last very long. The loss of Korinthos is certain, and I'd wager Thessalia would fall soon too. Gonatas' only hope is to hold out in Pella until a combined Pergamene/Seleukid Anatolia force arrives to bail him out. Even then, with Pyrrhos/KH dominating Heavy Infantry Central, it's likely they'll win out in the end. Gonatas might make it out by promising peace with disarmament and payments to Pyrrhos/KH.
I agree that Ptolemaic Syria would be overwhelmed and lost, however Aigyptos itself would probably be a tougher nut to crack. Perdiccas, despite being the regent of Makedon at the time, had quite a bit of trouble in his invasion of Aigyptos. Though they're not in the game, I believe there were fortresses such as Gaza that needed to be taken before a proper seige of the Ptolemaic core can begin.
On a side note, a Seleukid blockade of the Hellespont would cut off the Bosporos from most of it's customers wouldn't it? That'd also provide an economic incentive for them to go pro-Ptolemy.