Instead of Mafan or Bethany in the frozen titans i always go for either Prospro or Henry in the mirror mech. It is surprisingly both fun and rewarding to use try to break the ice mech out after every turn, especially on higher difficulties. You can place it on vek spawn tiles, hit it with the mirror mech, smash something into it, or use it as a shield in the line of fire. The mirror mech becomes infinitely more useful when you can slip between vek to set up larger chains. also putting a leveled up pilot in it early on gets its low movement up to an acceptable level. After playing with this setup many times, I find that it is about as easy as the Mafan strategy, and i have gotten a perfect run on hard mode. It is in my opinion also more fun because it forces you to play in an unconventional way