
The 5 upgraded cannons...I build those first (I usually do the 4 side ones, and then the middle one last).
Upgrade the ice ones to heavies first, then impact 1. Then upgraded the other 3 to QC2 (upgrade evenly, the middle one always gets the upgrade fist). Then the ice ones to Level 1, then the other 3 to QC3. Then the ice ones to Level 2.
Then I build 2 more QC3's, one at a time (not upgraded in the picture, and I did it like that so you could see them).
After that, I get all of those (5) QC3's up to QC4, and then just keep building QC4's based on what the ants are doing.