You're righgwigh haageana for the first, a very variable species. Asfor the seond, it looks as though the cenral spine is curved towards the apex. That suggests M. wagneriana to me\
The thirdplant is really nice, but Ican't place it at the moment.It might well be a sport in which all colour in the central spines has gone.That sometimes ocurs with mass production cultivation.
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Chris43, moderator