Thing is, you need more action points to make your incarnate even compareable to the widow
At level 12 and 10 points in summoning my bone widow has:
2708 HP, 404 physical armor
deals roughly 260 damage
My incarnate Champion has just:
639 HP, 202 physical armor/ 202 magic armor
deals roughly 160 damage
For just one AP more you get a summon with 3112 Hitpoints, compared to the incarnates 841, that also deals 100 more damage AND can teleport.
If you cast teleportation and power infusion on an incarnate, you already spend 4 AP, but you still have less than half the hitpoints of the bone widow and deal less damage.
I tried this out to the most extreme and made everyone in my party a summoner with enough necromancy to cast the bone widow, I can finish fights by just casting enough widows from outside combat (meaning that none of party members are affected by turn cooldowns)
This turns tactician into a cake walk, I shouldn't be able to win fights without any of my party members even being involved in combat.
I don't understand why Larian made them even stronger, when they already made combat easier in the first game.
Incarnates themselves don't seem that overpowered, but I'm not sure if Larian tested the non-summon skill summons and how they scale when you put as many points into sommoner as possible.
I'll go test this for a while.