Hmm, I see. Well, the thing with those corridors is that they're long, narrow and for a gameplay purpose they'll probably very boring parts, so I'd cut down on their length. Personally I prefer to keep combat to certain well-defined area's and have corridors or paths in general connect them, where I try to keep these connections as short as a few seconds running and usually a bit wider than this, to give players the chance to avoid fire. Putting in a little cover now and then isn't a bad idea either.