Tell me a game that allows you to run a server in a cluster. There is no game. Yes, there are games that runs the matchmaking service on a server, inventory API on another and then the server where player plays on another server(csgo). But the server where thry actually play is still one server. Not really possible for a game server. Well, there is, but not working like that, because you would have to sync everythhing between the servers which will make them need more resources(cpu, ram) and use a lot of network just for syncing between servers. That would also add latency because of the network talk between two different servers, which in a webserver works very good, but in a game server that you want to have ping as low as possible, not gonna work.
Also, ragemp uses low resources, if you optimize your script then you do not have a problem. If you need more resources, buy a dedicates server.