Go into a fresh map and copy all the Orc Burrow abilities, Battle Station, Cargo Hold (Orc Burrow), Load (Orc Burrow), and Stand Down and stick it on the Human Farm and test the map.
None of the buttons appear in the command card of the Farm, and it cannot load units. The same thing happens with the other transport abilities. Trying to use a custom Cargo ability with the vanilla transport abilities results with the buttons showing up, but the ability is entirely broken.
EDIT: I should probably go to bed. It's one of the simplest fucking issues in the Object Editor that completely slipped my mind. You can't have two abilities with the same name, it breaks the one with the ID further down the line. God dammit. (Or I'm probably just babied by SC2 'cuz this issue does not exist in there)