I disagree... You don't actually fight any mind flayers or dragons, only imps which as far as I know are relatively low level challenge.
I expressed my opinion about companion levels many times, but the short version of it is - they are not as powerful as they claim to be or want you to perceive them.
Yeah thats the first problem, was in hell only fought imps, LUCKY
was on mindflayer legendary ship, no high level guards, LUCKY
Gale: Im a super powerful like imba archmage lover of mystra lvl 1 wizard Hero: ok? thats yeah ok dude suuure i belive you
Wyll: Im a hero to the people Blade of Frontiers probably heard of me? Hero: Cool is that that demon aura i sense from you? Wyll: no no im just regular hero Hero: Yeah i just saw you use eldrich blast you sure you got nothing to do with demons? Wyll: No NO NO trust me im an engineer! Stupid as fuck
Astarion: Hi im a awesome rogue Hero: Wow thats som HUGE fags you got there. Ast: no no no! later that night Ast: I just need a litte blood cause you see im a vampire but a good one! Like in twilight! But i love torture and killing. Also i lost all my game breaking powers so i can still be with you level one guys. LUCKY!
Dark druids trying to take over an groove but once again we get lucky they only sent lowlevel druids! LUCKY!
Gith knight with a red drago shows up but leavs before taking care of group needed to stay like 5s to disarm us LUCKY!
not to mention Raphael and Ast's master
everything thats happening are high level campaign stuff but me manage to survive anyway so freaking lucky its just not beliveble