I have seen 2 tangs get along just fine in a 90g tank.
I have also seen 2 tangs spend months trying to kill each other in 300g tank.
Is there a chance it will work? Absolutely. Is there a chance you will end up with a dead tang, or have to tear down the rockwork to remove one of them? Absolutely.
It all depends on how you view your livestock, and your tolerance for risk. Most of the better reefers on this board wouldn't risk thier livestock, don't like uncertainty, and wouldn't do it. And I realize "better" is completely subjective, but you are asking for opinions.