If that’s the concern it’s better to have each server send a signed counter of votes coming from its own users to the hosting server for the post being voted on, then people can see which servers three there’s how many votes from.

This provides the same privacy as intended before (your account host knows your votes, nobody else does) and you can see which servers are acting suspiciously while allowing everybody to get a consistent view of votes (the host simply tally up the votes from each other server, and offer up the signed counts on request)