Nah, Imoen was begging to be dual classed to a mage even in BG1. Her high intelligence was there for a reason.
Also, it seems to me that the party Bioware gives us at the start of BG2 was the one they considered to be the most widely used by BG1 players. Imoen because you start off with her, Jaheira and Khalid because of Gorion, and Minsc and Dynaheir because of Boo.