[vhcook]

I'm thinking the drawbridge will get the least use, as it's a visibility blocker, easily opened from inside, and from outside requires a simpler motion to open than the sally port.

The portcullis is at least slightly transparent and is a harder obstacle to resolve, so I think it will get used more in spite of its height. The cheval de frise requires some specific design to deal with as well, so I expect the overall usage to be fairly even (and aligned with strategic knowledge of the opponents).

The category B and D defenses really depend a lot on the opposing drivetrain, so I think they'll level out.