You can definitely run a RS-485 in a "peer" (all stations share control) network. For example, you can use addresses to define a message path, any station can send a message to another station by indicating its address in the message. The only catch, as mentioned above, is that without master control, two stations might decide to transmit simultaneously. You need to accommodate that somehow. Some systems that work this way, just detect errors caused by the data collision on the bus, and re-transmit until it succeeds.
You're asking if you can have more than two stations - this tells me you haven't done any research before coming here.