Why don't you start writing and see what happens. No-one can really tell you at this stage if that idea will work, because it's yours and you haven't told us anything about the actual plot or context. It sounds fine to me, as a place to start, but obviously, as a story it will have more bones, as it were! Do you know what the goal is that they're both striving for? If you know that, and they do have something more tangible (as you say) to work towards, in their different ways, then I think you just have to go ahead and start writing. See what happens. If it doesn't work, give it up and try something else.
I heard Richard Curtis (writer of Love Actually, Blackadder and all sorts of other jolly things) on the radio this morning, and he was talking about coming up with plot ideas. He says that he can't really sit down and start working on one idea - he writes down about 17 ideas, sketches them out a bit, and chooses the one that sounds least awful to expand on.
By the way, I hope you don't mind me answering this question - I'm not a very experienced writer, but I have finished a first draft of one of my novels :)