Quite possible the earliest versions 1.1 and 1.2 happily accepted units with a building_conditional in the EDB
whereas that broke to a great extent in the later versions. As well as causing CTD when building conditioned units were right clicked I think that was when it acquired the bug where you could only have a very limited (4?) number of building conditioned units available in same city before it CTD'd.....?
Whatever changed that might have changed other things to do with the recruitment capabilities, but I've got no idea what version the 32 max limit was tested on.