[cypher]

Levels aren't usually recommended with pairs or groups, they create areas that one or more hams can become territorial over & this increases the risk of falling out & fighting.
ETA I forgot to say that the height of the levels in those cages can be a problem too as it's quite a long drop, especially from the higher level to the one below which couldn't really be softened with deep substrate like the lower level (if I'm looking at the right cage!) so there is a potential for falls, this would be even more of a risk with a group as any ham being bullied by another may have trouble getting away without falling.