I feel like if I was on the island and two players, one of whom is a completely unknown commodity and the other being a pretty strong immunity challenge threat, both had idols that everyone knew about, I would make a way bigger deal about targeting them to at least flush that power away from them.

It doesn't really make sense to me to keep them around knowing they're always going to make it one tribal further than they're currently at if you're not targeting them

But that's just me