I got really lucky and got a Teox the first time he was available. Have been using in hydra brutal since. Yesterday, I tried the A3-off, manual A2 twice, only A1 with 2 other lizardmen in my team. My damage dropped from about 2M per boss turn to just over 1M per boss turn. My takeaway is that your other damage dealer needs to have an insanely strong A1 to justify turning off A2 and A3.
I just got my 2nd Teox with the 1+1! I think I'll build a slower merciless build (my first is a 279 speed lethal monster with 7.3k atk and 331 CD%) and see what the tandem of them can do. My brutal and nightmare teams are set, so I don't see the value in splitting them. I'll just use the 2nd one in place of Krok'Mar. I wish I had Lazarius, Krisk or Sulfuryion, I'd have a busted good hydra team then! I have used Teox, Dracomorph, Krok'Mar, Nekmo, Sun Wukong and Maulie in Hard Hydra, hit for 1 bill dmg. I'm excited to see how much more I can do with 2 Teox's! Did find it interesting that no one else used Krok'Mar in their teams when you were running through all of the different team comps.
I have teox and that dude is sick!!! I would love to have a second one for other content in the game because I use my teox in arena. And even when he's slow he takes so many turns