From my experience clearing a lot of multiple merge profiles, I like to see the linkage of Bios with Sources as part of the cleanup process. For example, sometimes the sources are only listed at end of the Bio, with no in-line citations, so keeping Sources with Bio helps me figure out what is sourced. Also, often sources are Ancestry type with lots of duplicates of the same original source that need to be changed into one citation; I find this is easier when they are near their bio. Usually the redistribution into a single source set is the *last* step I take in the cleanup.
Presumably this tool would be available as an option to cleaners, but not automatically applied.
I suspect this would be most useful for small merges, which may be the bulk of the 811 errors now. Perhaps it could even be a default option when you do a merge?