So with all 2 servers being priority one, how would that even work with whats being downloaded
Downloads are divided into "chunks" or posts so, a 50 meg file might be made of 150 posts. If you have all servers set to the same priority, each chunk is handed to a connection to download across both servers. If the chunk fails on one server, it's handed to the other server to try. So, there's a natural chunking mechanism that makes is easy to divide work across connections and servers. After all the chunks are downloaded, they're assembled into a file.
If you have one server set to 1 and the other to 2, all chunks will get tried on the priority 1 server and any failures will then get tried on the priority 2 server.
If both servers a flat rate meaning the both have the same cost. There's no point to making one a different priority. On the other hand if one account is metered and the other unlimited, you make the unlimited server priority 1 and the metered server priority 2 so, it's only used when needed.
The reason you seldom need all the connections is because, unlike torrents, your data is only coming from the server instead of from a bunch of random people out on the internet. That means typically you get more data per connection.