having +15-20 more AC is a "unique" of its own
That's a meme. Stop chasing them. None of that AC is free or even close to it and it's not +15-20.
Play the game. You've got enough AC to avoid regular mobs just playing it as designed. Tanking can also be done with armor and good play (or you can take the initiative with several characters with enough AC to not be paper tigers). Then there's a few things that require different tactics because they're really good at attacking. That's fine. It's what we want. I don't get the endless chase for exploits and faceroll. You're defeating your own purpose.
I wouldn't mind having a couple more good armors earlier, but it's not like I've usually got a whole team of Heavy/Medium wearers anyway. Living Ram is available at end of tutorial. Rock of Nature and Flowing Scales at beginning of ch 2. Half-Plate +1 in Market Square then +2 with +2 CON in Irabeth's tent. Reg has +2 Full Adamantine.