Uhh, no it wouldn't. This would make Warrior completely unviable for pretty much anything at the Savage level or above. To put into perspective just how bad those changes would be, Thancred's buster in FRU deals upwards up 400k while Shiva broaches close to 500k. You quite literally need almost every GCD you have to survive without an invuln. In fact, Warrior is the only tank completely dependent on their co-tank/healers to survive phase 1 as they run out of CDs.
It's almost like as the difficulty ramps up their self healing becomes far less impressive. The irony is despite the criticism Dark Knight gets for lacking sustain in dungeons, it's a much more sturdy tank in Savage and Ultimate.