If you look at poultry husbandry books written over 100 years ago, even then they knew / found that the ladder style roosts that are iconic and cool looking are a bad idea, and for exactly the same reason you discovered. The birds all seek the highest roost they can, and will fight with each other to get there. So the best solution is to make them all level.....or at the same height.
Back in the day when nearly every farm kept a flock of chickens, as well as large numbers of back lot chickens in urban settings, proper housing for chickens was recognized as an important component of success. It had been studied extensively. What was true then is true now......and today is mostly ignored. We seem determined to reinvent the wheel......and it keeps coming out square.