Not really true, you don’t really need a VCA tbh.
If you use the inputs on the AK and feed these to the track sounds (tracks 1-4), so the eurorack sound goes through the filter and VCA of the AK then you have a full voice with just an OSC and Filter from the eurorack.
Track VCA and two more envelopes from the AK, plus pitch CV (CVA), a filter Envelope CV (CVB) and a couple of lfos (CVC + CVD) from the AK to the eurorack.
You can set the source on the pitch CV and envelopes on the CV track to that of the same track your routing the inputs to (rather than it taking info from the CV track), so it behaves like one instrument.