Titan (and Mythic) attack priorities

the glut of new heroes in this game also includes many more options for titan attack heroes. however, since we still have only 5 hero slots for titan attacks, how do you prioritize what to bring on titan hits, including (and especially) Mythic Titans?

in no particular order, we have

  • defense down
  • elemental defense down
  • big attack up
  • stacking attack up, e.g., C. Grimm + Miki (unless you use Guardian Gazelle)
  • damage increase (Motega, Franz)
  • critical chance
  • element (weakness) changes (Guardian Chameleon, Norns)
  • tile-affecting heroes

what would lead to the biggest damage numbers? and what could you afford to substitute with items instead of bringing a particular hero? (e.g., last week on Mythic Titan, instead of a defense down hero, i brought Mireweave because her attack stack stacked with Gazelle and used a Valkyrie’s Bane.)

(i see there’s a titan attack fundamentals thread already, but i think my question is sufficiently different to warrant a new thread. however, i won’t be upset if this gets merged.)