When the B-47 was being designed it was discovered in wind tunnel testing that at high speed the ailerons on the wingtips when deflected instead of adding or detracting from the lift would instead twist the wing and essentially cancel themselves out; this was due to the structural differences between a straight and a swept wing. The solution was to add inboard ailerons much closer to the wing root, which are perfectly adequate at high speeds but lack sufficient control authority at low speeds, and so the outboard ailerons are still required (stiffening the wing structure to make the outboard ailerons effective at high speed would have added too much weight). The outboard ones are locked when at high speed, and only the inboard ones are used; I do not recall if the inboard ones deflect when the outboard ones are used or not, but from what you are seeing it appears that they do. I believe that all swept wing aircraft have followed this same pattern; what you are seeing in the sim I believe is just the way that on the DC-10 the inboard ailerons work. I suspect it is accurate.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler