Interesting... so it could have been called the iPad 6 had they kept that naming scheme.
ipad
ipad 2
new ipad
ipad (was retroactively called the ipad 4)
ipad air
ipad air 2
I Don't see much rhyme or reason in ipad naming
ipad
ipad 2
new ipad
iPad with retina display (was retroactively called the ipad 4)
ipad air
ipad air 2
I Don't see much rhyme or reason in ipad naming