You misunderstood the premise. The first company pays $91k after training. So it's not $111k, it's $100k during training, then $91k after that. More competitively, it would just always be $100k and the second company would have no advantage. In fact, the first company has the advantage because it will be easier to initially find the people that need training.
On top of that: The second company presumably still has domain-specific training of its own to perform, and will have to un-train the hire in other ways. Makes more sense to just pick up someone new.
