If Piccolo, Gohan, Krillin, Tenshinhan and Chaozu were able to use the RoSaT prior to the Saiyans arriving, would it have made any difference in the outcome of the battle?
Even with the additional training, the Saiyans would have won regardless. The entire purpose of introducing them was to be the next best thing. I highly doubt that Akira Toriyama would have them defeated so easily due to plot purposes.