Mutators die by hand as a priority target, there's relatively few of them on this particular map. And well, I use different variations of this one. You can move merging point around somewhat freely, so which path is longer can be well-regulated. This whole thing can be turned around on its head with a few blocks moved.

Good layout, but very uncommon for me. Do you use this with towers too? For myself, it looks like either one spawn gets too much time so the mutators can go insane..