Some design decisions are hard to understand, like removal of city walls from the tactical battles. First, the games wants you to micromanage the swings of individual combatants (which is currently not very entertaining, because usual tactical elements like flanking, formation bonuses or cooperative interactions between units [archers provided cover for footsoldiers in Fantasy General, remember?], and boils down to a row of units trading blows till one side falls), and then it says: "okay, you are defending the city, but the city is sorta not here."

Why? The sole purpose of building a city manually, deciding where each building would stand, would be to fight on its streets in case of invasions. Putting barrack next to a gate would have some sense then, but no, the design makes both minigames rather pointless. I can't pretend to care where I place my buildings - because it does not really matter - and I can't pretend to be excited by defending a city that is not even there. 

Siege defenses are just the opportunity to make tactical battles tactical - the attacker must gather significant superiority, and be prepared to take losses on the walls UNTIL they are breached, or somehow compromised. The wall breaches or opened gates create chokepoints that are interesting strategically, archers on walls are at an advantage, and each siege engine you bring have its pros and cons. Magic could play a tremendous role here, giving you another dilemma - raze the city to the ground with powerful magic, or try to preserve valuable buildings?

Another abstraction oddity is the representation of unit groups. How can a single attack kill three soldiers at once? Or how can all simultaneously attack at once? The unit groups act as a fatter version of a normal unit, and it seems very confusing to me. For most purposes, they are just the same unit with more hitpoints, and perhaps better attack? 

Also, the detailed look on a city is a wasted opportunity too - starved city could look differently visually than a happy city. Sieges could leave scars on the buildings. Border city at war could have armed citizens in the streets, patrolling, while a peaceful city could have napping, content, happy townspeople.