Currently the numbers are based on what felt right. I chose 10% more damage 'cause any other number felt wrong in comparison to the other attributes.
Same goes for a lot of other numbers.
I'll see how it plays out ingame, as that's where figuring out what needs changes will truly take fold.
It's not unlikely that encounters throughout the game will be rebalanced around player power level rather than the other way around though.
Crit/Might are multiplicative damages yes, and I don't like the way high ground is applied but I don't have any plans to fix that atm. Currently you can't even get bonus high ground damage and it is instead a static 30%. May be reduced.
Crit is something I wanted to be a multiplicative damage that was relatively powerful, but required investment on your character's part that could otherwise go to something else.
But I think you are misunderstanding Dex. It could be looked at 4% more AP and therefore 4% more damage per point, but if looked at in that way then it's basically a buff to everything you do and that aside if you chain abilities together using your full AP you'd probably be able to get a lot more than a 4% buff. It's not about having more AP, it's about how you use it.
However people decide to balance their Might/Dex and their other attributes is probably alright with me.
All of that aside, the mod I'm trying to make here is to make combat less about killing the enemy and more about surviving the encounter. My current plan is to buff enemy health/durability substantially so players would have difficulty killing enemies. This applies more to the late game when it's pretty easy to one-shot everything on a battlefield with ease.
If I do my job right, hyper-focusing on a damage party will leave you without enough CC to deal with the enemies before they kill you; you shouldn't be able to end a fight within 1 turn. Even 3 turns is a bit too quick for me.
If you want to worry about Damage Per Turn then play vanilla DOS2. It will be important for maybe 1-2 characters, but stunning enemies will be vastly more difficult so making sure your damage characters can actually live is also important. Damage does not equate ability to stun in this.