I play with Zerg most of the time as well and I think i made a similar mistake and was in awe at how much of a difference the queen made in the game. I don't recall this being a big factor in the campaign portion of the game but to be fair the last time I played that was several years ago.

I wonder how many people realized this a bit later because its funny that almost exactly the same scenario happened in my own gameplay. I would see these massive aerial armies from a team-mate who had the same amount of Hive bases as I did and was just thinking... how the hell are you producing so many units at once :)