Sorry if this has been asked. But what's the load order of two bsa?
Assume two mods edit a vanilla script for example and both are delivered as bsa. If your load order is modA then modB does that ensure that the script the game will use is the one that came with modB?
This would require a link somehow between esp and bsa imo, am I right? Does naming your bsa the same as your esp help and is recommended (upload to steam does that)?

The load index of the associated plugin determines which iteration 'wins' unless there's a loose version of the file(s) in which case it/they 'win'. By virtue of nomenclature, the game will automatically load a BSA that matches the name of a loaded plugin. This isn't true of the CK, thus the need to add DLC BSAs to sResourceArchiveList2.

So, you say that if I have modA.esp + modA.bsa and modB.esp + modB.bsa then the load order guarantee that the bsa's are sorted? What about if I don't give the same names to the bsa's (like mod_B.bsa instead of modB.bsa)?