I wonder how much faster than Legion your friend wants to play?
I've played a few games now, and even the first two, basically being familiarizing games, were both done in well under an hour. It's a pretty quick game I'd say; especially movement of units is very simple, where just the unit leader is measured and the rest is placed within a certain range.
But obviously, YMMV
As an aside; before the current blooming of Star Wars miniature games by FFG, I had originally planned to port the Infinity rules to a Star Wars setting. Which would be just about the opposite of what your friend is after!