Sooo
I have a few points.
I think the interface is absolute crap. Everything requires a billion clicks, and there is no information. There are no shortcuts, if you havent researched a technology you need to click 5 buttons to get to the actual choosing a tech.. And the skill progression of any unit / army / agent is really difficult to understand, trying to build a good unit (ala Shogun 2) with and end goal of perks in sight is impossible. Any perk / benefits (eg civilisation wide perks) have no information. Its basically a shot in the dark what you choose with eg, pirates, characters... The tech tree is hard to use too.
The agents are worthless. In Shogun 2, a good ninja + some cash was worth an army, and could, dependent on chances, hold your flank. that was awesome.. Here, an good assassin cant make an assassination.
On higher difficulty you get to the point FAR TOO EARLY where there is no real challenge any more. Mopping up the map is mindless and i'd rather start again. Even playing as carthage (the Rome 1 INCREDIBLY HARD MODE), i landed an army on the italian peninsular in about turn 20.
Oh and the client state bullshit is so poorly worked as well that i ended up assembling 1 army for each region, taking MY client state in 1 turn so i could have the fucking province. An you can walk into enemy territory without having to be at war, then go to war with your armies right at their gates. Utterly stupid.
Battles, you've covered. Generals, you've covered (the old retinues...). Good units, armies, you've covered. Specifically i'd in battle say that cavalry and elephants and phalanxes are amazingly weak; while archers and Roman infantry are brutally overpowered.
Autoresolution is far too tempting 99% of the time.
tldr, Yes. Shogun 2 Rome would have been amazing.