I used to play like this, but with shockwave troopers instead of snipers. Can't fight mutant + chem combo because orcas can't destroy chems 90% of the game.
I play a similar deck with wolverine instead of the Orca and MLRS replacing the pitbull for a bit more lategame point holding and it feals good. Orca is a bit more aggressive (also to the harv) than MLRS and Pitbull is more flexible. Will give it a try.
Use Orca to quickly take out chem buggy. This deck has counters for everything. Just make sure you end the game quickly so the opposition doesn’t deploy Advanced Tech units.