Having played to a decent length several games of the big campaign of Hannibal as Rome, I am getting the sense it is not very balanced for PBEM. Here are some observations:
1. Although the game events seem designed for Hannibal to march over the Alps, in PBEM typically Hannibal lands by sea in southern Italy, where the Tarentum card is played to give him an immediate base of supply. A smart Carthaginian player will just avoid the hassle of marching over the Alps. Rome can't cover all the landing spots and Hannibal has a decent chance of winning even if he does a Normandy-style invasion into the main Roman Army (which, if they mass in one spot, pulling in the legion from Sicily and assuming they had time to raise the extra two legions by then, can muster seven legions with auxiliae)
2. Hannibal, before he ages, is so God-like that, assuming he fights with his forces in mass, every battle is a foregone conclusion where Rome gets slaughtered and loses 8-10 morale; yes, he was pretty successful, but it seems that even a Dictatorship buffed Roman host (say 8-10 legions) entrenched in good terrain still gets beat badly
3. Hannibal also, once he has a city, rarely seems bothered by supply issues and his army replaces its numbers just as fast as the Romans, which seems strange since Rome is on its home turf. I can understand the locals who joined Hannibal replacing their numbers quickly, but not the elite troops Hannibal had brought from Spain and Africa. In the game, assuming all events are played (all three Dictatorships plus the extra two legion when the Pirates are defeated at the start) the Romans can have a maximum of 13 legions, whereas Livy notes that by the year 210 they had 21 legions.
4. Hannibal, of course, increases his stats with his victories, while the Roman consuls swap out every year, so even if you get a good one, he is gone before long
5. Despite the morale-balancing events, the way AGEOD games typically handle NM means that once Carthage gets 40-50 NM ahead, the battles become even more pointless
6. Once Carthage gets bored of slaughtering the Roman armies, they can just park atop Rome itself, thus preventing any more legions from appearing and waiting for the city to surrender
7. Although Rome historically adopted a Fabian strategy, the Italian peninsula at this game scale really doesn't leave much room to run
My overall sense is that the most adaptive Roman strategy in Italy - run away for eight years (100+ game turns) waiting for Hannibal to get old - is not the most enjoyable for either player. Yes, there can be action in Spain and some of the islands, but once Hannibal has cleaned up in Italy he can hop a boat, leaving a flunky to hold down things, and go wherever the Romans are in Spain and beat them down.
I'd love to hear from experienced Roman-side PBEM players that I am wrong, but does this all boil down to waiting for Hannibal to turn gray? The campaign doesn't seem too fun in terms of balance if that is the case. Yes, I know he did win huge victories like Cannae and Trasimene. But not every battle, even in his prime, was that one-sided.