Which tank is the best for accomplishing the mission? Which tank did you use for accomplishing?

So far I reset the mission 5 times:

GSOR 1008 (23/25 and 22/25 Internal Critical Hits)

Tortoise (19/25, 23/25 and 24/25 internal Critical Hits)

I tested arty also – nevertheless it only get tracks as critical hit and none internal.