You can't dissociate parts of an individual just like you can't say that this part of the clock is so so but the alarm bell is great. What counts is the overall, if I may say holistic proposition of what you are evaluating. Does the person fit well in the team? Are they bringing value in one way or another ? It shouldn't be that important to evaluate the specific skills of a said person, but at least recognize what they achieved (or missed) and try to understand why, and then make a picture out of that. Likability cannot make up for actual results (or lack of), or at least not very long.