I've done enough research to know that .ESMs hold records, and .ESPs modify fields in records or add new records.
What I haven't been able to find asking the Google Oracle, however, is the level at which .ESPs track record changes. If I have two mods, and one changes field A in a record while the other changes field B, with load order A.esp -> B.esp, does B clobber A even though they technically don't conflict? Or is the loader smart enough to track changes in individual fields, and only overwrite where a specific field is in conflict?
For context, I have a mod where the only master records I'm going to touch are the RACE records, modifying the SPCO and SPLO fields to add a racial ability to all playable races (at least to start with). Is the game smart enough to not clobber the model data for someone using a aesthetic mod?