I'm pondering how to best use the mechanicum Macrotek Apex and I'm starting to think it might just be three Krios, which feels a bit janky if you have all these other tanks.

All the other vehicles already have AV14 front and enough hull points to take a melta hit, you basically can't use the Macrocarid or Triaros anyway because it can't transport anything worth shit if it has the Macrotek keyword and the Karacnos is going to be in the back. May as well take a bunch of cheap tanks and boost them up to 14/13/10 7HP with amazing speed. The Venator laser is pretty mean against anything short of AV14, since D3 means it'll chunk dreadnoughts and EW TEQ, and the basic Krios gun is a monster of a template for 135pts.