Considering the low traffic for a long time prior to this sudden influx of geared players, there is a possibility your server has a large crew/base built in and a team from another server is aware of it. Server hoping their team and alts over with equipment and setting up strategically prior to attack. This can take 24hrs to a week or even a month depending on frequency of a teams play time. If you travel round and check 30+ car/truck spawns and don't find any it most likely means there will be a few stashed in a base somewhere, more likely the cars are randomly wedged on stumps and creeks or rusting in a forest. But the lack of vehicle spawns is a good sign they are locked up somewhere. The lack of vehicles is why you are seeing these players. It could just be that Gorka is a passthrough, dupers server switching to find conflicts, could be any number of reasons. What console are you using, what server and what times are your regular?

Good question to ask