1. "Cleave Burst" Formation
This formation increases damage by using Soul Link from Grimm's ult to link targets, causing all targets to take the same damage.
Then, players can increase the team’s damage with Amaltheus’ ult, allowing Amaltheus to reach maximum attack speed for a short duration. Amaltheus's Cleave passive ability causes all 3 targets to take damage. Under the effects of Amaltheus' Cleave and Grimm's Soul Link, all 3 targets will take damage twice on 1 basic attack.
In addition, Tigris' ult allows both Tigris and the enemy to lose the same amount of HP, and thereby also increases Tigris' damage through the passive 2nd ability.
In the end, placing Tigris and Grimm in position 1 is recommended as both Heroes have healing skills, with Tigris heals 10% per cast and Grimm heals 30% each time the opponent is defeated.