Mordor , Lorien and Orcs haven't horses.
All units have approximately equal movement speed, except horeses. Mordor have nazguls and Morgul riders. I didint see elfes and orcs( Misty Mountains), but I except something that they fit that.
This isn't true. Do you talk from multiplayer or singleplayer? Because the balance is for skirmish 1v1 not for epic battle.
When you know that you can't win a fight you must retreat and your units will overlive.
Reason is that why, every time I try to retreat I lost half of my unist while they retreat(While they get formation to start to move, and where is a lot of units that is much slower) so better let them to fight and die they will stop enemy units for some time, and only if u have outpost with 2 towers to stop enemy units if u are outnumbered. He constantly push and his units is lvled up after 1-2 fights. Enemy also gets reinforcement. There is no way to stop them, and with battle ram's (op, they have a lot of resistance to meele attacks) ur base will be destroyed. You lost game. Logicaly is PvP,multiplayer, because AI isnt so smart, to do this to human player
I only play skirmish, and I think all modes needs this ability to retreat.
Rohan have powerfull horses, farmers are weak, they cant fight with farmers+archeres alone, so ambush is only option that rohan win fights. You also can counter ambush with spears. There is a lot of options that you could do, but you cant retreat with succsess.