It is a duo. It's worked out by card element, not costs.
I met this 4 times in the top 50, and to my shock, took it down every time with a destroyer rush. Now that I have a decklist for it I can look for Lobotomisers and test it myself. 
ok.. but for the record, i haven't seen any decks like this besides rare farms, but they dont have the right towers. I made this deck as soon as i thought of and tested it so i could add it to my flying weapons series. i didn't realize i was copying another deck

and i dont know if this is the best combination of cards either so free to post any modifications you made
