Yes. Group #6 is optimal because everyone in group #4 appears selfish and uncaring for others. Group #5 has the moral high ground, but actually voting with group #5 is risky. Therefore the best option is to virtue signal you are in group #5 and get the moral benefits, but vote with group #4 and guarantee survival. Group #6 gives you the benefits of both.

This is similar to Newcomb's two-box paradox, where the optimal strategy is deception. The winning play is to preemptively convince everyone you're only going to take the second box, but then actually take both.