I took some time to fully check the save,which was tough due to high 30's(C) temperatures and humidity... it's hard to concentrate .
Firstly, even tho Blubmuz is confident that diplo is assured, why not have the contingency of conquest? We are very close to the self-vote pop limit, but if we add slavery to the civics change list, we can whip empire wide to wipe quite a bit of pop off. I see no reason not to declare on Pericles immediately. The troops in Ravenna will take 2 turns to get to Thebes regardless, but declaring now gives the western cav a chance at making an impact.
PPP:
IT-
Shift some airships from the west to Ravenna. The infantry on the galleon cannot make it, but we can shift the garrison at Lahore to Agra, which in turn can be shifted to Ravenna. The GG will add to the mace and hopefully make it to the front. DoW Pericles, move stack toward Thebes, and western cav toward Rhodes/Ephesus, depending on defenders. Promote and upgrade pike GG.
Move Rome's cavs to the Antium stack. All border cities on cav duty to be whipped/bought in case of conquest. Move GS to 5th, GA to Ravenna. Take workers to the front (all hands on deck!)
263
Move stack into forest next to Antium.
" " next to Thebes.
" cav next to Rhodes/Ephesus.
Switch civics to US, FM, slavery, and FS??
Whip if necessary in a pop sense. Rush inf in border cities if necessary. Rush RC. Found AlCo.
264
Take Antium. Take Thebes. Take Rhodes/Ephesus. Vassalise AC (he will right now, so this is not an issue). Vassalise Pericles

. Lots of whipping if necessary. Can someone remind me of the exact self-vote pop limit?? Is it 2/3=66.67%??
265
Take win vote. If this is not possible, keep pushing onto Perc.
266
Win...
The attached screenie is some amusing AI stupidity, just for fun.