Does tanking carry more responsibility than most?

[Aureliami]

well turn 1-4 we have picked up an extra dps and solo healed these turns before. also turn 2 is so easy now with this enrage strat. a well gear'ed healer can solo heal it with 2 extra dps.. 1 tank 1 heals goes dps. We 1 tank 1 heal this turn all the time.

Yeah coil 1-4 is easily solo healable.

The only reason turn 5 is very hard to solo heal(but not impossible) is RNG. You need a 2nd healer for when the healer gets put in conflag or prison by dreadknight. So the 2nd healer only really needs to spam some heals for 5% of the fight and the other 95% not do anything...
.. and you can still beat turn 5. But that 5% of the time when you need a 2nd healer will probably cause a wipe if you try to attempt it with 1 healer, sadly.