I think you can have multiple accounts on the same world using signed too. One time I was botting mining on a few accounts and on one world I noticed that someone else was botting because they were taking the exact same path as me. Turns out it was one of my other bots that randomly chose the same world and logged in aha..
If it's rsbot you're using, you can't. Even if you did, every 6 hours it will auto log you out and all the bots will not log in at the same time and only one will be back on after 6 hours.
I think you can have multiple accounts on the same world using signed too. One time I was botting mining on a few accounts and on one world I noticed that someone else was botting because they were taking the exact same path as me. Turns out it was one of my other bots that randomly chose the same world and logged in aha..