So I never really used cannons before until about a week ago, and in the process of learning how to feed cannons, I noticed something was off. A ton of crew were only carrying 1 cannon ammo at a time, even though they're capable of holding 2.
I think this is a result of crew being programmed to "wait" until the next bit of ammo/ power is made before giving up and searching elsewhere. But even when you have several ammo factories right next to each other, you get a lot of crew waiting in line to pick up a single piece of ammo, which makes them half as efficient when transporting ammo to the cannons.
As a fix, crew should wait until there's at least 2 cannon ammo to pick up, and overall should be less patient about standing in line to grab cannon ammo. This needs to be distinguished from going to power core for batteries, as right now I'm almost certain they're using the same protocol.