I've been playing a medium sized map with underground on Lord difficulty, as the default difficulty was seemed to be too easy. I also jacked up the number of players to 8 from 4-5 as there seemed to be too much room to expand on a medium map.
Things seemed to be going well until a neighbour decided that I was the rock he was going to break his empire on. Despite having entire stacks of tier IV units, I managed to successfully defend myself. The only cost was every hero with stack I had, plus my leader.
Luckily my production levels were high and I had decent gold reserves, and managed to get back up to speed relatively quickly, except I was still using tier II and III units. I conquered another ai and eventually made another surrender. Not sure what causes a surrender vs. fighting to the death, although in this case I think he had no cities left and maybe only 1 stack of units? Not sure. He was also the same race as I was (Tigran. I was a warlord).
On the plus side, my necro neighbour wanted peace so he could work on another enemy, but on the minus side, 3 ai's decided to invade me at the same time and I lost some vassals and 2 strong cities (both of which I had taken from neighbours earlier).
I'm playing with Seals and Beacons on, just to see what it was like and to explore the mechanics. I'm slowly being ground down as I'm being out produced. I just can't keep up with my neighbours, despite catching and killing as many of their stacks as I can, I just don't have the gold income to pay upkeep on many more units. So I'm stuck with what I've got, and the ai just keeps building full stacks of tier III and IV units. I'm still stuck at II and III (mostly III) and have yet to build a tier IV unit.
One of the ai's that jumped on me when I was already hurt is about to win the Seals victory. I never made it into her territory, the fog of war is still covering most of her empire. I also never made it underground. I wanted to do so, but there was always someone to deal with above ground. So that means any ai's with cities underground are untouched, unless they are fighting down there too. They should be.
For my next game I'd probably try the same difficulty level, 1 or 2 fewer ai's so that it's not *as* crowded so war doesn't break out right away (the current game an independent city was captured by a neighbour before I could finish the quest they had given me. Like turn 5 or something crazy like that).
Not sure what race/class I want to play next. I like the sheer toughness of the orcs, which is somehow different than the hardiness of the dwarves. I'd like to try necromancy, but I still don't know how undead expansion and cities work. Undead combat seems to be as expected. I will say that having despair stack AND last 3 turns is a bit crazy. 3 turns and no stacking, or a maximum of 2 stacks and 2 turns would be better imo. Having defeated a much, much stronger army earlier in the game, I had high hopes when a Necromancer came calling with less units and lower tier units. He despaired everyone down the worst morale possible and proceeded to devastate even my best units as my damage was reduced to nearly nothing.
After multiple games, Dwarven Firstborn are still my go to tier III unit. I know what I'm getting and they won't be destroyed too quickly even if flanked. If they get to level they become serious beasts. I just don't have that much experience with other races. Tigran war breed are good, but warlords get war breeds no matter what race they are. I under estimated the prowlers in the early game. Their martial arts has a HUGE impact on how much counter damage they take at that stage.
Pounce is insane. Teleporting free backstab is great. I'm struggling to think of a standout Tigran unit. Sphinx are good, but they are not as hardy as I'd like. I expect and need tier III units to be able to soak up damage. They are too expensive and take too long to make to let them die fast if/when flanked. I never did get a Manticore Rider made.