As you have asked for feedback on units for beta 2 here are some thoughts:
Three main things to consider:
1. The influence of STR in a battle2. Amount of turns to produce a unit3. Powerful bonuses on certain units.All above things are related and must therefore be considered as a whole.
STR does not currently effect the battle as much as it should. As a result 1 turn units do stand a very good chance vs 2-3 turn units with higher STR. The battle calculation could be slightly adjusted, perhaps a 18 Dice instead of 20.
Some units (eg pegasi) with very powerful bonuses are being produced too fast.
Some examples (I take these numbers out of my head, they might be slighlty inacurrrate):
2 turns Pegasi gives + 1 stack // 5 STR // 24 Moves and can fly.
If you compare the Pegasi with Elephant.
Elephants are produced in 3 turns has -1 negative effect. 8 STR and 16 Moves (no flying )

I think the Pegasi and elephant are equally powerful, I think the Pegasi should be 3 turns as well.
I think the terrain bonuses are well balanced.
Making STR more influent and adding 1 turn to production of Pegasis would make a lot of differance and benefit the game balance.
Some minor tweaks:
Griffins are fine at 2 turn production cycle, though their movement could be reduced (would fit well with their city bonus).
Orcs with +2 in open terrain makes them a bit too powerful. Perhaps lower the STR with 1 or slightly lower their movement.