There should be no latency between out channels at all... unless they are feeding different soundcards that are not clock synced.
Or... the compressor is adding latency... use a compressor that does not do this... my Levelizer compressor section should work with no phasing problem.
Perhaps there is a problem with the way the signals are being mixed outside SS... I would suggest making things much simpler and assign all drum signals to one out stereo bus and let SS do the virtual mixing perfectly.