I don't mind the long-ish build times, at least for the early part of the game 'phase 1'.
In Civ it could take 6 turns or longer to build a spearman ... and I think a similar notion held true in MoM. Unit times are not always fast. I think what you mean though, is that its turn 400 and I'm just now exiting the early game (getting into the 'power' part of the game).
Personally I don't mind wandering the game doing random quests and killing random monsters ... as for me that is a large part of what 'fun' IS in a fantasy game.
Yes, we don't get to see 4 heroes face off 4000 thralls or anything (at least on normal), and the size of armies is fairly small ... which leads to a single fireball killing most of any enemy army (whereas a truly large army would be the size of 10 fireballs).
-> as a side note, as much as I "LIKE" AOE spells doing damage*#of enemies, its just really hard to balance magic vs melee. It was easy(er) to do in FFH2 I think because the game was so abstract that you couldn't do 'real' magic, and-> then there was the pillar of fire ...
-> Hmm, if we scaled down stats with loss of HP (not 1:1 but maybe 1:3)-> including attack and defense ... then we could have spells only cause a Max % of damage, leaving mage's tiny staves (or their body guards) to knock in the heads of the weakened army.
Anyways, yes (just like in MoM or AoW:SM or Kings Bounty, or any other turn based tactical fantasy game) we don't get to see a level of large-scale realism in our armies, but I think that makes up for itself with the sense of adventure, the levelling up, the really cool items, and the magic.