LAST EDITED ON 05-03-14 AT 11:06 PM (EST)If he goes ahead and votes out Spencer, there's absolutely, positively NOOOOO doubt in my mind Tasha rounds up the gals for an all-girl alliance. Not only would it be smart, it would also be ridiculously obvious.
The problem is that the girls have no reason for wanting to go with Tasha over Tony. Everyone should be well aware by now that Tasha is probably the biggest jury threat out there right now (probably even over Spencer), so there is literally no incentive for them to do so, other than a general, "We hate Tony" sentiment.
With two idols, he has a free trip to the F4, so his only objective is to get there in a condition where he doesn't have to win to move on. And I feel he is more likely to be in that situation if he plays it safe than to keep playing Loyalty Roulette with the ladies.
Going the "safe" route, his main concern would be Trish/Kass/Jefra teaming up in the F5. If he really really wanted to oust Jefra, then maybe he should've waited a round (in the Final 6), so that Trish/Kass wouldn't have anywhere else to go afterwards. They still couldn't go with jury-favorite Tasha, and stealing Woo might be tougher for them.
With his two idols, he should've been able to steer the next two votes in whatever direction he wants. But now he's making it more difficult for himself.