After playing, for 'almost' 2 years, I've noticed, that of everything that has changed, the arena has not, sure, the monsters are a bit diffrent, but the arena is 'still' a bit overrun by tefusangs. But this isnt my point.
The monsters within the arena, IC'ly should'nt be able to thrive, let alone 'want' to thrive, in the blank, triangle they live in. Notice, when you are in the riverling pit, or the trepor pit, all you see is dirt. What 'I' Feel is IC, would be to have a habitat, so to speak, for each pit of monsters, as a colony of trepors wouldnt be able to survive in dirt, they would need various grasses, plants, water, the riverlings would want a small pond, the velnishis, might want some rocks, the dlayos might want a stadium, the tefusangs would want a field, the coamtis would want a bush, or a hole, the tlokes and arnagmas might want a tree,
An analogy is basically saying, you wouldnt get a hamster, and place it in a fish tank, with no fluff, fake house, tubes, and food/water, without those it would die, Its the same for the arena monsters, So i just hope this is considered.