Most common is L20 rhino which is the 4 pack plat pack but people don't like people with plat packs.

I recommend L56 rhino tho I've seen they are not bad but they are probably best at that level for rhinos.

I would say endgame was best for rhino but too many str players and nerf kinda ruined rhinos at 76 tbh ( reason why I retired 76 rhino )

Good luck!