This is a purely theoretical question, so I am unsure if it will even make sense:
Imagine that there are two planes which are inclined at say, 45° to gravity. One has infinite friction and the other has zero.
There are also two perfectly round, and infinitely hard spheres (no deformation), and similarly, one has infinite friction and the other has zero.
The sphere with zero friction is placed on the plane that also has zero friction; and vice versa.
So assuming gravity is the only force acting, and equal starting conditions (apart from friction), and that the one scenario would have perfect roll, and the other would have zero (and zero friction losses): I think that the sphere that rolls will always be behind the other since it has to convert some energy into rotational energy. Is this correct? I know this is probably trivial to prove but I don't think I am competent enough to do the math yet.
Further extending that idea, does that mean both spheres, at any point in time, would have the same total energy?