https://www.dropbox.com/s/m4it1npbkp1v4e4/Small%20Concept.bawb?dl=0
Here's my quick concept. The Gryphs are walking a bit too much by default, so it would be nice to have a kind of wall that only lets projectiles through. Spikes are there so you can't safely use cover. Rather than room size alone, I guess it comes down to condensing level design so that there's less walking and projectiles don't fly for too long.