I totally came up with the same idea after i finished my first playthrough yesterday. I thought im going for a challenge and play only with my 2 maincharacters.
But i had in mind how different certain steps of the game might become if i only had 2 characters to act with. the +80% vitality only applies to the base vitality which means only through your skill points? that means life from items doesnt count i guess. So i only get a big bonus through the AP regen. So Glasscanon was automatically the next step for me ( or will in the future ). You definitly want to have 4 character-skill sets on 2 characters. You can do this with the increased talentspoints + the gold you save from only equiping 2 chars ( you can buy skill and talent points every level for 20 k).
But to fight this amount of skills you need glasscanon in order to do enough stuff. In my playthrough basicall 2 melees killed the whole screen in a few rounds even in endgame while my other 2 chars basically only did 4 or 5 things, like hast, feathfall, bless...and thats it, i allways skipped their turn after that lol.
I ended up with 2k and 2,5k on my melees, so i know you can push your health high enough to be viable even with glasscanon ( i played on hard ). And i was even lazy with my gear and char improvement till the end since it was just to easy.
The big problem with my specc is... that i decided to play a rogue character with dagger
so i dont get 50% resist and 25% vit from arms i guess at least.
my second char is a wayfarer type. so bow + all the importan magicspells.
dont know which addidtiol skills i will use on my rogue later, maybe fire or eart fro buffs or summons as distraction.
But double lonewolf + glasscanon defintily will work. Just make enough gold to buy the 2 talent and skillbooks every level ( i guess the vendor refresh every playerlevel ).