Single vs. Multiple NPCs

[The Punisher]

I am trying to understand the NPCs better and in my searches I've seen issues with "too many NPCs". I for once had some issues in SP with some in-game npcs (weekqueay, Trandoshans, etc.) not spawning because some other mods I've downloaded and I was wondering about the best way to include npcs, so my question is, is it better to have a single NPC for the same versions of the character or a separate npc for each character version.

 

For example, I use a pack that contains several versions (skins) of the same character and contains an npc for each version. Is it better to have a separate npc for each version or a single npc that includes all versions?

 

Thanks in advance for any feedback.