It is all a question of balance. The brakes themselves don't care what axle they are on. While it is an odd combination like you wrote, it could be done. You would need a 10lb residual check valve in the drum brake line, and a 2lb in the disc brake line if the master cylinder is below the floor. An adjustable proportioning valve would also need to be installed in the line to the rear. You would need to do some slow speed testing to check your brake balance, and work up to higher speeds. I would suspect the fronts would lock up long before the rears even with the proportioning valve wide open, but there are too many variables to be sure.
Keep this thought in mind regarding your proposal...Just because you can, doesn't mean you should...