I have some experience with syncing sound with video, and one thing that can help in a very subtle, but noticeable, way over long stretches on the timeline, is to make sure all of the audio sources are in the EXACT SAME format before trying to sync. So, let's say the SBD is 16/44 and the AUD is 16/48, then take the UAD down to 16/44 into a seperate file FIRST, then bring in both 16/44 files to do the sync. That's not really what you are talking about exactly, but that can really help keep the sync for long periods of time.
You can also "zoom" in to the point where are are trying to sync in two ways usually. First, zoom the timeline way in so you are only looking at asec or two (zoom in to the horizontal section of the timeline), then blow up the wave signs really, really big (enlarge the vertical representation of the sign waves). This can help you visually "see" the sync point. You can also do some weird things with polarity, like purposely get the polarity opposite of each other, then figit with one track until it "cancels" the other track the most, then flip the polarity back.
Just some ideas, but they come from the video side, so maybe doing a matrix is different?