>>48389941>>48389964My hunch is originally Cofagrigus was Ghost/Ground, because of its association with sand and deserts and stuff, but they made Golurk later that gen and decided to revoke Ground from Cofag.
All these years later they remembered this and thought oh hey cool now we have the opportunity to make it Ground, without thinking about it logically.
Remember also, the designers don't have a final say over the Type or anything else from whatever they design.