I want to add some characters to my story with different ethnic backgrounds, mainly for realism. But I don't want to really address the issues of race; I don't have the inclination nor the understanding to go beyond the cliche. What I'd like to do is include them in the story and treat them like any other charcter, without regards to their ethnicity.

Which do you think is the greater affront to cultural sensitivity? To exclude them entirely, or to gloss over their ethnic identity and risk portraying them too much through the lens of my own cultural background?