...would it not be better to use a single compressor signal path and just add on more sidechain action..
maybe take a $10 graphic eq board and patch it into the sidechain...
oh thunking about it, you want distinct dynamics control of each band---so there whould probably need more VCA's, but simplcity in the signal path is also important,
i think a cannibalized 10-band would be useful in the sidechain