I've had sorta the opposite problem....I play with my bestie; who hosts.

Our most common glitch is when returning to a saved game, that I will be in control of the NPC formerly attached to my character and my bestie will be controlling his character and all the NPCs
Sometimes I'm in control of the NPC who was formerly attached to my character and he's in control of "me", his character and "his" NPC.

The fix that most often works is to go to camp, dismiss all NPCs, I leave the game completely. Then rejoin and it's just the two of us, we then "recruit" the NPCs we want in our party. Yes, it is a total PITA.

At one point when I was trying to rejoin, the multiplayer display was showing him as host and 1/4 (we have NEVER had it as any more than just us 2). He left the game and we eventually got it resorted.

WHAT IS NEEDED:

-an IN GAME way to assign characters to players

As for the idea that one would use quicksave as opposed to Manual save is silly. The manual saves are the only place you can put a deliberate description/info, and if you later play solo, you will wipe all the multiplayer quicksaves due to the way the save setup has been done (which again, I would like to see improved).

Actually, if the "quicksaves" would include (and be linked to) the profile used, AND could be renamed (i.e. changed to Manual saves) it would solve a lot of problems.