Even if you give him all that, he is still much worse at defending from defense compared to other heroes.
My point is: to use his +6 regeneration as an advantage in tactical combat by:
1. Raising his defence to level where he wont get more damage per turn than 7 - 12 even while being swarmed. Its doable till your enemy has 4 units in stack with boar spears or similar (11 x 4 damage with traits might be around 50). While his defence while defending should be around 60.
2. Raising his intiative to get that regeneration going as often as possible.
It is good because unlike healing it costs nothing. You still can buf him and he still can equip some armor not from shop like chain with 2 def ans 10 magic rezistance or glowes with 2 def and 2 accuracy or some other rare armor.
I dont know with what heroes you are comparing him, but i think he stands realy well at his role as secondary hero, maybe you just dont want to try and see how it works, bacause i tried and i liked it. Same fits for mausolos, but he is even better because he already has starting 20 def or so and his HP is about 100 just from the start.
I am not saying he should go explore or atack. He probably much better for keeping your back safe or at stopping some sneak armies which you did not notice in time.
His comrade with trhow rock ability for me seems much much more usless and hopless.