Oh, I'd agree that a ABC Warriors series with a single artist - in this case Henry Flint - is preferable to one which leaps from one artist to another. However, if it's a choice between having a guest artist like McMahon & the coherence of a single artist on the whole strip, I'm afraid I'd still go for the former. If it were any other artist, I'd probably say no, but I'm a massive McMahon fan, so...
As for his more recent style - I'm pretty much sold on it. Ever since he reappeared (in the Meg at least) with Howler, the readership seems to be fairly cleanly split; you either love it or you hate it. I love it.
It may not be Sky Chariots or Block Mania, but it's just as refreshing & powerful.