The miniscribe had its own pattern if I recall and the standard drive that same to be did not fit it well. When Apple started to move to other brand drives, a different more universal sled was needed. Or if the end user upgraded, a different sled was needed for proper fitment.
I've got one of each handy, dunno which is from which machine. Just checked, I thought he one with the LED was from the SE, but it has a 2MB Sony FDD and the two slot cage has a Sony MP-51FW-23, so I had it mixed up.
I think 2 slot/4 slot probably works better than top/bottom/whichever way it is in the IP pic.