The Baccus Empire doesn't exactly play like Imperial Rome of 1st century AD (which is the image most commonly ingrained in pop culture). Rather it's more like late medieval Italy, i.e. what the Western Roman Empire could have actually been like if it survived into the Middle Ages as opposed to a warring cluster**** of city states.
That still doesn't stop them from having in my opinion, the most broken roster in the entire game. They have the best KO's, the best lord armies composition in field battles and a common line of troops that can counter even top tier KO stat line units (e.g. gladiators, pikemen and armored crossbowmen)
They literally have no weaknesses if played right, unlike other factions which feel missing out in some category. Best of all, the cheap easily trainable crossbowmen/heavy infantry combo make paramount garrison troops in terms of cost effectiveness, which is something very important in late game.
If you're finding Noldor battles to be too much of a challenge (and they're intended to be that way) you can easily befriend them early on by following their small squads around with a minimal party and joining each scrap they partake in with other random mobs. Alternatively, as lord of a fief, you can release their prisoners that are periodically placed in the prisons of the castles or cities that you own, which is even faster.
Large snake armies are actually a boon, since they yield large amount of xp for you and your party as well as much needed gold, prisoners and loot. As marshal you can gather your faction lords together and have them chase down those pesky snake hordes whenever they show up. Once the initial wave of Serpent Priestesses and Anaconda Knights (which Empire KO's have no trouble dispatching) is dealt with, the rest of their 500-700 or so army is a pushover. If you're lucky you might even get a qualis gem drop from Maltise.