If you have Gale in the party, make sure he learns Longstrider. It gives +3 meters movement ALWAYS. And if you cast it outside of combat since it's a ritual it takes no spell slots. Oh, and the effect lasts until the next long rest.
We literally kicked Gale back to camp the instant we got him and didn't bring him back out until we needed his arcane/int rolls to talk to the librarian in Act 3... so he basically sat at level 1 forever until suddenly he was level 12.
And because Snuffles is a sorcerer and isn't familiar with D&D he didn't realize wizards were different and had to pick what spells they wanted to "ready," combat was "interesting" when we accidentally got into combat.
But our party composition has basically been:
Snuffles, Evocation Sorcerer
who is also controlling Astarion, Thief Rogue, who is just there to pick locks and disarm traps
And maybe who is controlling whoever is plot relevant and needs to be in conversation but generally Snuffles does all the talking because CHA 20
GasBandit, Open hand monk/Thief Rogue
who might be also controlling Karlach, Berserker Barbarian, if we aren't doing anything companion-quest related
or who would be controlling Shadowheart if we are, because somehow (bug) she convinced herself she's my lover even though I've never given her any indication I was interested much less actually slept with her but what the heck let's keep her happy I guess
So basically Karlach is our default 4th member unless we specifically need to advance somebody's sidequest.
On a side note, I am so grumpy they found a bullshit reason to nerf the Chest of the Mundane.