1) Str or Vita don't make a bad tank, cause str or vita tank should keep aggro and be healable, off course not be able to keep aggro/ get too hard to heal, is what we can call a bad tank,
Str tank have to be more exeperienced with the CD than a vita tank, because if the Str tank is too hard to heal, it's a also a bad tank, at this rate he should go for vita and get more exp with the CD before wear str accesories. Str tank don't have to say to a vita tank he is bad, because there good str tank caring about be tanky with a very strong use of the tank utility and bad str tank only carryng about dps but a hell to heal, this bad str tank should go back to vita and get learn to care on being tanky before wear str accesories.
2) Str accesories is not only 5% of strengh
3) Provoke give you the aggro of the previous better aggro player on the fight +1, so pull with provoke give you 1 of aggro. it not a skill for pull. it's a skill to get aggro back from a other player.
You should use Blood bath/fight on flight/ shield lob/ scorn/ the rage of the halone combo to open as MT, it's a good opener and you don't kill too much of usefull CD to open the fight.