I will play with the companions I "like" (which does not necessarily mean that I like them) and don't think about perfect party composition. Maybe I will play on "Normal" instead of "Hard" if it gets too difficult.
My first groups in the EA (main as Ranger, Cleric, Barbarian, Fighter, Sorcerer) consisted of Shadowheart, Lae'zel and Gale and partly Astarion, I totally ignored Wyll. I learned later that Wyll is quite interesting, a strange guy.
At the end of EA I decided to play as Rogue which was never a class I liked that much in any game, but as which I can imagine my character the best, because a Rogue is such a humble, boring, normal choice. I had some difficulties to decide between Lae'zel or Wyll in the party. Lae'zel would be better for gameplay in combination with my Rogue, but I don't like her that much, so it will probably be Wyll.
My motivation/thoughts for my group:
Shadowheart: powerful class, even with Trickery domain; as person she is mysterious, like it, but, quite honestly, it's more cause I want to sleep with her.
Gale: no need to talk about Wizard class; as person I like his soft rational scientific way, and that I got more and more frightened by him and his problems.
Wyll: Warlocks are stronger than I thought, and his flying minion is fantastic and often a lifesaver against ranged enemies; as person he is such a funny mess, I'm curious.
