keep watching for over couple days. I think you should be fine with lots of cave. I love to watch all mine. I would be devastated if any of them died.

Its been a week and they are still doing great. I have the opportunity to watch my tank at least 8 waking hours a day and no aggression. Im gonna say adding them all at once is the way to go. No one has picked or started to defend a territory so what I am left with is 4 awesome fish weaving in and out of the whole tank.

I think it still too soon to tell but hopefully everything stay the same as it now. Fish does change their behaviors over time.