I only use one amp, too, a DRRI on about 5, so not too different from your setup. I wasn't saying you can't only use one amp.
What I mean is, if you're going to really crank a really small amp to push the power tubes for all of your gain, I think your clean options are more limited because gain and volume will be interdependent. That's where a larger second amp could be handy for loud clean tones.
But of course you can get by with a single medium sized amp, even if it's not crystal clear, and especially if you're playing roots rock or blues. And whatever works, works, right?