So, are you "mike'd up", Mike? Sorry, just had to do it with that handle!
I don't do custom parties in PoE1&2. I prefer using the Companions and Sidekicks, because so much of the charm of PoE1&2, as well as the old BG1&2, was from the Companion interactions.
I will say though that if I had a gripe about the PoE1/2 companions it'd be the lack of a good, gruff dwarf companion. In PoE1, Sagani didn't really exude any sense of being a "dwarf". And I don't recall Konstantin in PoE2 exuding that either. Maybe part of it in his case is being the class choice. I wish he'd been something that felt more "dwarf", like a fighter or a fighter/priest. Maybe it's just that I like the fantasy dwarf stereotypes, but I do. And having a dwarf that doesn't feel like a dwarf makes me feel like there isn't a dwarf companion. Heck, Durance felt more like a dwarf than either of these two. Crap, the devs could have made him a dwarf, with a dwarven avatar, etc. and I don't think that anyone would have batted an eyelash.
Maybe part of my problem is that I really like the fantasy stereotypes, and it seems like the devs like creating companions/sidekicks that go against the stereotypes, which makes them less enjoyable to me. But I'm going a bit far afield from your question.
I'm enjoying my current party quite a lot. My PC is an Aedyran Wood Elf drifter who is a Swashbuckler (Black Jacket fighter and no-subclass rogue). And my core party is my PC, Sherwyn, Eder (pure fighter), Xoti (priest), and Ydwin (pure cipher). And the 5th slot I use to run different companions through, depending on what quest I'm working or what enemies I'm going to be facing. That is, certain quests are "best" done with a particular companion, like each companion's personal quests. And in other cases, certain companions are better suited to the enemies you know you'll be fighting, such as having Pallegina along to help deal with the vampires, er… I mean, the fampyrs. I'm to the point where I don't really have a single fall back companion for the 5th slot, though I do prefer to fill the slot with a melee fighter, since I use Xoti and Ydwin as archers, and my PC Swashbuckler I use about evenly in melee and at range. My Swashy's primary weapons are the sword Modwyr and the double-barreled arquebus. She's far and away my best damage producer. And I love to have Ydwin buff her with that 9th level cipher spell that enhances penetration. All in all, they're a fun core group to play, at least for me.