Piranha,
Bats - Move 20.
Orc - Don't care seemed fine as it was
Light Calv - YES
Dwarf - Disagree. This unit and the Pikemen are identical 1 turn 4 strength units so they should move 8 to compensate for that strength advantage. This unit is an excellent city defender and works awesome on hills with it's 1 movement pt and +2 combat.
Elves - Str 2. This means the 4 strength units (pike/dwarf) move 8, the 3 strength unit (hv Inf) moves 12 and the 2 strength units (orc, elf, lt infantry, lt cavalry etc) all move 14+. Much better balance for the 1 turn units to follow that rule.
Wizard - Disagree. I'd never build one if it took 3 turns. It's basically a Giant with some extra movement and bonus vs fliers (which makes it ideal for air defense thanks to it's high move). I'd instead prevent it from EVER being in a capitol city. If you have to make a change, reduce the Wizard to 4 strength so it can still be useful against fliers but isn't much of an assault unit.
Unicorn - 1200 seems a bit much for me just to cancel terrain bonus's outside cities. 1000 or 1100 would be better since it has to compete with a Pegasi only costing 1000 for a +1 stack bonus.
Elephant - Increase the strength to 7 as well. Makes it more valuable as a combat unit given it's slow move.
Ghost - So this means 1 Ghost is really 30% since it gives itself +5% in addition to it's own 25%? The cost of this unit seems a bit high at 1600 gold. Probably shouldn't cost more than 1300.
Devil - I'd prefer it cancels the negative bonus's like the Medusa.
Demon - Interesting idea, but how is this going to work? Are you going to be reducing the enemy strength when it fights a demon to compensate for the walls? What if there are no walls (ie L2 or less)? What if you already have siege units negating all the walls? This seems like it's going to end up buggy/hard to understand-use.
Griffon - 18 moves. 16 is a too few for this unit. It needs to keep up with Pegasi and heroes.
KGB
P.S. If you want to make the 3,4 and 5 turn units better value in terms of combat then put many of those units back to their original strengths.
Dragons - 9
Demons/Archons - 8
Elementals - 7 (I know they were 8 but with the +3 attack bonus 7 is fine)
That along with the Elephant going to 7 makes most of the 3 turn units all 7 strength (other than Griffon/Ghost) plus they all give some kind of stack type bonus. It also means they won't get killed so easily by the cannon fodder 1 turn units esp if the Elf + Lt Calv go down to 2 strength.