LAST EDITED ON 04-19-10 AT 01:32 PM (EST)
They didn't weigh all the variables (or at least we didn't see it).
For example, even if they had the part about the female alliance right, RussHell could advertise that he has an HII and use it as leverage to build a new alliance and get someone else booted. He wouldn't necessarily have to play the idol at TC.
And, someone else on the Villains tribe might already be in possession of an idol -- maybe even RussHell himself by the time of the Immunity Challenge, if there was a clue at the Outback Steak reward and RussHell was lucky enough to find it.
It should have occurred to the Heroes that the Villains could potentially come into the merge with two HII's (as we know they are doing), while the Heroes would have given away the only one they had.
I don't think it was the stupidest move ever since as you say sometimes risks need to be taken but I agree this was a poorly calculated risk.
A tribe glows in Brooklyn