Take my Hp un-buffed (It’s higher than what the site says) 11804.
1% of 11804=118*15=1770*30S=53100 damage in 30 seconds.
That’s 5 times more than the amount of HP I have

Rejuvenation
Heals the target for 1060 over 12 sec.
1060*5=5300 (level 70), without any + to healing.

83.33R*5=416.65 per second.

Regrowth
Heals a friendly target for 1215 to 1355 and another 1274 over 21 sec.

60.66R*5=303.33R per second.
1215+1355/2=1285A*5=6425 (level 70), without any + to healing.

Lifebloom
Heals the target for 224 over 7 sec. When Lifebloom completes its duration or is dispelled, the target instantly heals them self for 600. This effect can stack up to 3 times on the same target.

224/7=32*3=96*7=672 (level 70), without any + to healing.
600*3=1800 (level 70), without any + to healing.

With said healing so far = 14197 give or take (rough sketch up) this number =’s crap when you add in the +healing the druids are going to have. (In a little bit, or after work I can throw in a real 70 druid with stats) Coefficients
Add up Vampiric Blood 35% and 15% more HP (changes math)
Add the 4%*15%=60% from Blood Aura. (changes math) If all said are Blood with Aura.
Add in the -20% to damage taken from IBF. (changes math)
Death Coil/Death Strike. (Changes math, but not used in equations due to no set number(s)).

(Other healing)
Paladin - Judgement of Light

Just looking at the numbers, I bet you could live all the while doing 783+962/2=872.5A DPS+

.2*783=156.6*15=2349
.2*962=192.4*15=2886

2349+2886/2=2617.5A DPS… lol, wow.
Add in Trueshot Aura.
Add in Battle Shout.
Druid – MOTW (changes math)
Priest – Fort (changes math)
Paladin – Kings (changes math)
Paladin – Might

That right there is a lot of said math that needs to be added to get a Ball park number. However, with an imagination, one can have, and the rough numbers I have given (Can we say… 4 Horsemen)? I have no doubt you could live, and the DPS you would produce would be indescribable)