So you want to link your releases against discogs and musicbrainz, and you expect that there must be a 1:1 assignment. What I don’t like is that apparently you take it as granted that this always must be possible.
At the discussion Freso gave us you see that there is not a broad agreement on when two releases should be separated in musicbrainz.
Actually, I think there should be some limit on which minor differences indicate to create a new release. Adding a new release for each minor difference in the mould SID might result in an insane number of releases and massive data duplication (which always indicates a bad database design).
But I recognize that there is some interest in the differentiation of those minor production details. I think the best way would be to introduce a sub-release entity “production variant” (or whatever) for keeping track of those. The discogs link could then be set on release- or on variant-level, depending on the data state on the discogs side.