When I DM I don't exactly discourage players from making weird and wacky characters. We had an orc wizard/monk muticlass in the last campaign. Adventurers are inherently not "normal" people.
The only thing wacky about this build would be if the orc would be as powerful a wizard as pure wizards of the same level or stopped being an orc because his entire biology suddenly changed and the ASI moved around.
Both things sadly or probably possible in BG3.
