How far can mitigation tanks get in Lordaeron?

Hi, my question comes from the fact that the bosses are tunned to hit harder, so raids with higuer difficulty require the safest choices for tanking. I know that Bears and DKs are considered best suited for Main tanking, but can a prot paladin do it in the same gear lv that those two?

Also, I know that warrior is considered the worst main tank and second to paladins in terms of offtank capability, but how far can they get in Lordaeron? is it posible for them to tank in heroic ICC or RS (main tank and offtank)?

I have both Prot paladin and Prot warrior at lv 80 with almost the same gear lv (5k gs according to Gearscore) and I'm planing to progress then both to the same lvs of gear and equipment to compare how different or far from another they are in terms of capability in all the content.

AFAIK tank tier list is:
1. Paladin
2. DK
3. Bear
4. Warrior

Paladins are top tier and always "get far" to put it that way. As for Warriors, you can try tanking with it but people won't invite you. I'm not gonna go into why or why not because it'll just spark another one of those "it's viable if you're not bad" several page discussions. Let's just say Paladin and DK are safest choice as far as tanking goes and the community sticks with them.