Considering the huge support for this contest (with the exception of Flops and Sniper), there's an amazing principle of life that can be exercised here with regards to possible issues of pre-conceived bias / favouritism.
The principle is that if everyone has a biased advantage, then no one has a biased advantage. By what manner would this work or be executed?
It should be innately clear that server administrators are the most trusted members of the server, otherwise, they wouldn't have been accepted for their respective positions. As such, each mapper participant should be able to choose one server administrator to be a participating judge in the contest. Therefore, the greater the participation in the contest (which is amazing!), the more inputs will be available towards the judging period.
However, it shouldn't solely be those admins on the judging panel, there should also be two guest mappers on the judging panel since they'd also be highly qualified to present their input. Finally, the community following the testing of all the maps should be able to vote for their favourite map, which would account for one vote on the judging panel. In addition, the votes of the judge panel members will be anonymous amongst themselves, the contest participants, as well as the community as a whole. This is to ensure that no inner or outer bias takes place.