The "design decision" doesn't require you to switch characters.
"I feel if I don't hire..." You are switching characters around, based on your feelings, and complaining about the game design?
Laz (Gith) tells you she has a plan, which you FELT meant that you needed to break up your preferred party.
Wyll has something to do with Goblins, so you "have the feeling" you need to switch your party again.
Maybe you will miss some bit of Companion story, by not having them with you at certain points.
From a design stand point that allows you to play with who you want, and catch up on "Missed" content later on with a replay.
