Like law said, there’s a pretty simple solution for removing any crew bias;

Don’t announce who built what until after the vote. Now, obviously, if you’ve been around a while and explore a lot, you might be able to recognise the odd build as one persons, and another as someone else’s.

On the whole, though, this would simply remove most of the bias, because only a select few people can identify who built something from a picture, and even then, it would not be regular.

So, just trial it without names. Might work better, might not; worth a shot though.