Hmm, if you're not wholly confident in character acceptance you could ask someone to help you and keep character submission secret. Having too many judges (AKA open submission, where everyone plays their part in character acceptance) doesn't tend to work all that well as people have different ideas about character judgements (it's very subjective). The main upside to a secret admission (the characters can be revealed after the tournament starts, I personally recommend this as well, but only from what I've seen in the past) is that it stops people unconsciously or consciously creating characters to combat others. You'd think it would be difficult to cover every opponent but even at low powered it's possible to tack on a few extra defences to protect you from a character's unique form of attack you might not have thought of.

Still, that's just my two cent, it's completely up to you what you do with your tournament. Don't take anything I say as anything more than recommendations, it's your show.