Make patches of substrate with rocks in between to make a space for each male (and lots of extra spaces so they can choose and some are left empty). The male will hover over his patch of substrate and the rocks will block his view of his neighbors.
With one big rock pile one male can try to claim the whole thing and chase all the other males away. It is high enough.
Page 3 a pic of rock 5 piles on a bench. This was for a 72" tank so figure 3 rock piles for a 48" tank.
If you look between the piles you will see that a male could hover over the substrate with rocks behind and on both sides...glass in front. Same idea behind the rock piles. Eight male territories with four in front of the rock piles and four more in back of the rock piles. Females can lurk in the rocks above and swim around/through to escape.
This will give you the idea, there are many ways to achieve male territories that have some way of blocking sight lines between to some extent.