The number people are saying is not an amount that adds with each new player but is the amount used per each person on their systems. In theory dial up systems should work just as well but if you are getting max speeds of 21.6 then I would suggest moving j/k. All I could say is you could try and play and see what happens but I definetly would try and find someone or somewhere where you could get a faster connection just to at least download the game.
