Personally I would see Starlight as Strange with her skill in unicorn magic, and Twilight as Iron Mare due to her intelligence, and the fact she had all these technological contraptions and devices in her tree-library's basement. Captain America, I'd say Rainbow with the loyalty to their respective friends. AJ? maybe as Drax with the down to heart and blunt honesty they share.
But at the end it's up to one's preferences and views.