first off, all summons chase differently, one chase low float and makes it high float, and one chase high float and makes repulse and so on. I believe the solution here is to see what skills your ninjas have and then lap together if the summon chase it :)
and then we can go on about the blue, purple and golden summons (which are all the same but better stats, and golden chase double every round)
what is the summon that shows up? if it is chameleon it means it chase a 10 combo regardless of your ninjas skills.