It is more than theoretical difference Sunfire, Pyro, Firestar, Oya, Sunpot, Magma are all different and for this thread it isn't moot to show that. You can't down play that Pyro can make animated fire animals or Sunspot fills more of the powerhouse slot than the energy projector slot. What the writers do is irrelevant the point is they are clearly different they were allowed to they would be used different it is not like Jean Grey and Rachel Grey with exact same power that can't be applied any differently. Sunspot, Amara and Oya for example could be on the same team and you wouldn't really get redundancy. In fact Magma and Sunspot being around each made so they had to highlight the difference , In the same way Idie and Iceman were also different. The simple point was look a little deeper at characters