Yes, they will crowd. But, the evening "going to roost" time is when the biggest pecking order brawls take place. So, no matter how many l.f. of roost space you have, I suggest that you have 2 of them! If that were my coop, I'd lower the high one. It looks like the perch area below the fixed full length one is a stand alone unit that can be moved? If so, you could place that perpindicular to the other one. I'm not saying that you have to lower that top one. Plenty of folks do have high perches, and do not have issues with their LF injuring themselves. I'm just pointing it out as a possible concern.