Good point. Okay, I've updated the rack to the following:
I've added the Metropolix, it's definitely what I'm looking for. I also dropped the Javelin single VCA-envelope in preference for a full quad rack of envelopes and VCAs, so that I can gain some sustain for the Manis, the Ataraxic, and the uPlaits.
I'm also thinking that I'll augment the Metron with uGrids for the snare, hi-hat, and clap (via some logic OR modules, I'll be able to send gates from both Grids and Metron). That way I can generate entirely new drum patterns with the twists of a few knobs while still retaining much of the Metron's ability to control what's going on (particularly with the kick).
Wonderful. Now comes the painful part; the eons of waiting while I buy modules bit by bit.