I'm a fan of having multiple lost Summers Brothers. Chris Claremont considers his canon (Gambit); Fabian Nicieza considers his canon (X-Treme); and Ed Brubaker considers his own canon (Vulcan).

I've written a 3-part article that places the pieces of their canonocity into place so that they can all co-existent as "Summers Brothers." Peter Milligan seemed content with one important aspect connecting all of these (not spoiling for anyone who wants to actually read it). 

But the question is, should this even happen?
Does anyone care?
Are we all content with Vulcan?

If you're interested in seeing where I'm going with all of this:
http://deathtojohnny.kinja.com/gambits-true-identity-is-finally-revealed-1761097472
http://deathtojohnny.kinja.com/sinister-connections-1761715718
http://deathtojohnny.kinja.com/the-lost-summers-brothers-part-3-of-3-1761758261

 

Who was the best Third Summers Brother? (Result)

Gambit

X-Treme

Vulcan