Hacker specs question
 

In looking at the specs on a C50 Hacker motor, I see the 12, 13, 14 & 15XL add on. I think ths refers to the "wind", and I see different current draws and rpms associated with them. What does it all come down to when trying to match a motor to an airframe?
E.g. a 71", 14lb Warbird.
Thanks
John