Using less speaker cone area is what I do when using my Fender Super Bassman.
Into my 215 or an 810 it gets blisteringly loud and I would be seriously struggling to get anywhere near power tube break up at a level my bands play at, and we ain't quiet by any means.
But, into just one 115 (luckily my Super Bassman does 8,4 & 2 ohms) , I can push it pretty hard. I'm not usually going for full on power tube grind, just a touch of sweet break up, is what I'm going for.
Was the same with my old SVT2. I'd run that into an 810, LOUD AS! into a relatively inefficient 4 ohm 410, I could get it nice and dirty at ok levels too.
The WA is pretty much the same. Imo...