The only reason I can see why most of us use Tonton as summon for Nine Tails and Group Summon is that his chase is triggered by 5 combos and especially, it deals full single target damage. Other multi-target summons get their damage split evenly to multiple targets, so the damage dealt is less. People tend to use ninjas with chase talents that gets triggered by certain number of combos cause there's no other way to do a chain of attacks on those bosses. You can further maximize your damage output by choosing ninjas that are in line with your main character's elemental attribute.

Example teams like:

Azure/Mei/Edo Haku/GNW Tenten/Yagura/Darui/Kisame/Suigetsu

Crimson/Onoki/Iruka/Asuma WB/Deidara/Kurotsuchi/Yamato/GNW Kiba/Edo Deidara/ and some other Konoha ninjas with x-combo trigger chase

Midnight/Guy/Mifune/Darui/Sasuke/PB Sasuke/Danzo/Iruka

Breeze/Edo Haku/Kaze Gaara/Gaara/GNW Temari/Baki/Sage Naruto/Asuma WB

Scarlet/Danzo/Iruka/Mei/Yugito/Onoki