I think I would have to side with the OP on this one. Since Astarion seems to be the topic of choice let's roll with it. A lot of the dialogue I've come across with him has been very rogue. To have him as some wizard or maybe cleric for w/e reason the dialog would really feel out of place. Lae'zel and Shadowheart I can't really say the same for so far, but my god Gale especially rolled as a Fighter or god forbid a Barbarian when that's a thing would be jarring to say the least. And to a degree I think a solid character should be influenced and shaped by everything that character is for better or worse.
Background, class, and personality are entirely different.
