The music is linked with that roster, so after you add the music, make sure you do a roster save. Then when starting a franchise make sure you load that roster file. Or, are you saying you are already in a franchise and you just edited the players in the franchise menus? If that's the case then I have no idea why it wouldn't work, because that's the way I did it. Btw, I also can't stand the base running in RTTS. I like the stealing aspect, but the overall base running is terrible, I've made so many outs on the bases.