Pirelli quickly went the way of Conti, Vittoria, and Schwalbe in naming all of their tire models nearly the same as the other tires so it becomes a total mess to try and initially sort out when looking into tires.
Looking at the Pirelli site, I think 4 different tires are for the exact same segment/group of cyclists.
You shouldn't have 6 versions of the same tire model(not talking about widt or wheel size).