Jeff, yes, you can work it in a variety of ways . . . as long as the model gets done. Normally someone starts on it, and then sends it on to the other person. Like you can do a group collaboration and split up the different sub-assemblies. Someone who is good at engines can do that, then someone does the chassis . . . etc, and then another person puts it all together.
Two and more people can play, and have a blast.