In every other circumstance, the tournament rules state you must possess the cards, dials, bases, pilots, tokens, miniatures, and everything necessary to play a tournament game. Now they're saying you need to own a version of it, even if it's not for your current faction.
If I'm whining about the color of the cardboard sandwich, then I'll just proxy the TIE/x1 title; it's just a piece of arbitrary cardboard. What difference does it make that I never bought it? What reason would it matter that FFG printed it or I printed it? Why would we draw a line in the sand like that?
We're drawing the line the only place the line can possibly be drawn that matters; right where FFG says to draw the line.
