Observation is correct - Alexa is NOT a time-trialist, she is a racer. Times in races will only be a reflection of the quality of the competition. Cranny can run Ok on her own as can Cain. One type isn't any better than the other really, except when chasing records. All are too young yet to know how this will play out in races down the line - in 2 years anyway if all 3 are at the Olympic trials and trying to run 1500m. I don't see any of the three having moved up to 5000m by then - what would be the hurry. However, Cain has the proven wheels (sub-2.00 800m) to stay at 1500m. Whether the other two do as well will unfold during that time-frame.
2.04 is great for Cranny, and this will definitely help determine what events each will contest at World Junior this summer - all 3 can't race the 1500m - assuming they all make the team. With Judd (haven't heard much from her this year) and Hinriksdottir presumably doing the 800m, there is a medal on the table for that event (if Cain doesn't double) yet the 3000m usually has some wonderkind African women (likely overage but whatever) running under 9.00.