disclaimer: i don’t own an a4. but w/ that said:
aside from the mnm’s formidable modulation possibilities, think another structural level upwards … consider the fact that you have six tracks, each of which can be configured as either voices or effects, then connected into buses and chains of buses.
plus the ability to process outside sound … both synths can do this but again, on the mnm it can be routed anywhere in the aforementioned signal chain(s).
each track’s lfo’s cannot be aimed at other tracks. other than that constraint, i feel few limitations i don’t bring to the table myself.