I am currently playing a Spartan campaign on hard and expanding my empire has been pretty easy so far. Im just swallowing my rich but tiny and isolated neighbors one-by-one, and those that I do not annex get forced to become my client state. From other Total War games I remember that at least the starting phase was always a struggle - even on Normal difficulty, you had to fight to get to a point where you can expand savely. In Rome II, everybody seems to crumble under the might of my Spartan Hoplite stack right from the get go, despite the fact that the description says Spartas starting position was "hard".
So, maybe it is the difficulty? Is hard not hard enough?
What Id like to see: AI to its best potential, guarding in peace, active in war, that makes me actually consinder attacking a faction or not while still being reasonable (not filled with player hate "just cause").
What I really want to avoid: AI that recieves overwhelming buffs. On the campaign map, I do not want every piss poor nation to field multiple armies. I want to actually be able to cripple somebodys economy without witnessing that he still can afford everything because of a vast artificial money cheat. In battles, I want my elite soldiers to be "elite" and not witness Spartan Hoplites having trouble with some peasant rabble because of insane AI unit overbuffing.
Those are the reasons I stayed away from the higher difficulties in earlier games. Yet all of those games were still challenging, at least in the early campaigns - and everything that followed felt rightously gained. Rome II does not really give me this feeling yet as I seem to overcome my enemies too easily.
Frankly, I rather have a less challenging, but believable and immersive game than a challenging one that constantly breaks said immersion by means like those stated above. So which difficulty would you recommend?