I mean "one time where" is all you need to disprove a theory. If it doesn't work for all situations it's invalid. I love your hire tracker and it's a great concept. It would just need tweaked very slightly to reflect returning cards.
Zyxe if you could verify that data for 100% accuracy that'd be wonderful, but I believe you are correct. 3 specs of a type is just too limited and I haven't seen games limited like that.