However, I think in the long term, the American girls would be able to accommodate lots of new transitions, if they invested as much effort into them as they did into practicing their triples.
The problem is that during all these years, the American girls had the wrong strategy. In their junior days, I remember Caroline, Mirai, and Ashley focusing a lot on their jumps (and spins), but not as much on transitions. Wasted time. Better to leave out the triple-triples but to maximize the transitions.
The problem is that adding lots of transitions would initially cause the skater to drop in standings because she would struggle. The price is high to pay. (See what happened to Mao. It could happen to others as well.)
I will however say that Ashley and her coach are on the right track because Ashely has been working with Priscilla to improve her skating in general and hasn't focused only on the jumps.