This is a personal preference sure, but I dont need depth to my companions but I also dont want soulless mercenaries. Where exactly is the balance? Hard to say, the companions of PF:K was fine in how much "space" they took up but again there was just too few of them. So I guess its a matter of prioritizing resources.
Yeah, though differenciating companions in content might lead to "Deadfire" problem - with people being upset why some characters got more content then others. Though personally I felt it worked alright.
[in case you are not familiar, Deadfire featured companions and sidekick - companions had a lot of content, personal quests and, ultimately rather broken, relationship system. Sidekick on the other hand, had a short introduction, custom voice lines, some small conversation trees... and that's pretty much it. Until DLCs that is, that fleshed them out a bit].
