I think Scott and Fuller will start with Rapp as the 3rd safety and Lake behind him. I think they would probably like to trade Rapp in October but would only do so if they have confidence in Lake at that point.
I have to wonder if Burgess makes the final roster. Good special teams contributor but other than a few games his rookie year just has not been inserted into the defense much (139 defensive snaps in 23 games). The bulk of his 2021 snaps were that ARZ game on Monday Night when half the team was out.