Pretty excellent! You might reconsider the 1/4" outputs, though, and drop a mixer (possibly w/ VCAs) in instead. That way, you can mix/attenuate up in the RackBrute and send the resulting audio back down to the MB2s's audio in and final-mix in that box. Pairing the Drips w/ the DFAM is a brilliant move, also, but also pushes that need for a mixer.
I did a test layout along similar lines, myself...have a look at the DAMN YOU, ARTURIA thread under 'Racks' from a few weeks back. The sort of patchables we're starting to see now really encourages this sort of thing, and I think it was really prescient of Arturia to come up with a unitized design that pairs the MB2/2s with an attached Euro cab. Granted, that build is more extensive, but it's interesting.