I love this idea. I want to automate the process as much as possible. Community ears are great, but a combo of tags + votes would be cool as well. The issue is we HAVE to get stuff out of the channels if they are off topic ASAP, else the judging quickly loses appeal. We've been aggressive about it this month and have noticed significant increase in battles judged. So I think for the short term ears and engagement are what will work best. Longer term we could move to a model you suggested.

-Daniel