I doubt that one can be so exactly sure of being able to make up 11 sec. in 1500m. But it's beside the point. She could have eliminated any risk by tailing Valby right away. Except for team psychology I don't understand what the advantage for KT should have been in remaining with the pack so long or the disadvantage for other contenders.
With slight exaggeration one could say that both Valby and Tuohy ran like one can if one is superior to all/most of the field. But both "tactics" are extremely risky in a professional or any field with more depth.
As I am usually not following NCAA I wonder how often they were similar races on (sub)professional level (and shorter than half marathon) where someone ran away early alone and was caught after haviong a 10 sec. or more lead. It's bound to be rare for obvious reasons. The closest I can think of (and it was no way as extreme) was Frerichs at the Olympics (and it would probably only work in the event with least depth, i.e. women's steeple).