Your tortoises will do fine together for a while...maybe even the rest of their lives. Male desert tortoises fight, but sometime when raised together, they get along until they reach sexual maturity. I always adopt them out in two's as hatchlings because they do better when there's competition for the food.
Try feeding your babies packaged salad. The one I prefer is called Santa Barbara Mix.
Im in AZ, and these guys are uber protected and sacred by the almighty game and fish. You cant even legally move one off the road onto the side if you see one about to get hit. We have all around ridiculous wildlife laws in Az, but they are what they are. I feed mine dandelion and clover weeds and a few dark leafy greens. I have had him since a young hatchling when he came into my emergency clinic for being attacked by a dog of some sort. People found him and just brought him in, having no idea what he was. I took him and nursed him for about 6 months (his recovery time) and kept (after getting the okie dokie by our wildlife Gods, game and fish). I love my little guy, Cooter, though. Wouldnt have traded the situation for anything.