I don't think it really works out better when some birds have to take lower roosts. The low birds hate it and tend to keep trying for higher.
We have a few different setups here, and the most peaceful flock is the one with enough room on the top roost that everyone can sleep there. The bossy ones just clear a space around them, the under-birds sit together (there is enough length to provide room for that).
In the shed with both high and low roosts, there is a nightly shrieking and flapping and disturbed warning calls upsetting everyone, because someone tried to fly up higher and got pushed down. It's very dramatic. And persistent, it doesn't seem like established pecking order makes a difference in how high they will aim for.
At least, that has been my experience. So same-level roosts are on my must-have list for coops.