I'm presuming that these are all 60 hp Moog skiffs, and you're using the existing ones that came with the DFAM and M32.
I wouldn't make the third one yet another voice. Instead, consider what's in the two Moog patchables: sequencers, VCOs, VCFs, etc. Now...what are those synths lacking?
First up, some clock modulation could get those sequencers to behave in some rather complex ways. Logic could be useful here, too.
Another thing the 60 hp Moogs lack is a comprehensive selection of modulation sources. Adding a Batumi and a Zadar here would blow that limitation away, though...and do so in only 26 hp, provided you include their expanders.
Now, that Chronoblob2...good choice, but you'll want to exploit its feedback path insert. Some simple bandpass filtering in there could be fun to get the delays to degrade in an unexpected manner...or a mono reverb, perhaps, to turn the delays into a blurry ambient wash. In either case, using something 4 hp and smaller should be fine due to the case limitations.
Mixing...mmm, nah. The Moogs output line level, so you're probably better off with an outboard mixer that can also handle your sax pickup. By putting all of the level controls on the same mixer, you can get a better handle on your balance between the synths and your horn, plus you can then globally process the overall mix with ease.
I'm also presuming you're aiming at something of a John Surman sort of thing here, btw...not exactly easy to replicate, since Surman used EMS synths as a rule, and those have a very different sonic character than Moog stuff.