If you are referring to the iPad 2 (2011) and iPad 3 (2012) then yes they should be compatible.
I remember now, they changed something with magnets and iPad 2 covers made by apple would still work but the third party ones didn’t anymore. So original Smart Covers by apple for iPad 2 should work with 3.Yes I mean the iPad-2 Apple Smart Cover which was released in 2011 and the iPad-3 which was released in 2012. So you are saying the Apple Smart Cover should work right ?