Possibly not THE catalyst.. definitely a reason.
He is far less 'reactionary' than many inside mids... especially ours !!
Some players are mercurial in that when they possess the ball they suddenly seem to have space where there's none. Gus has a slightly different take on that....he seems to harness 'time' . These extra moments that manifest allow him to better think the next move. He's generally very clever with possessions, seldom wasteful... that's gold, that's class.
Where some players can often be where they ought not, Brayshaw manages to hunt the ball and be where he can effect something.
It's a rare commodity...physicality with nous.
He is very important to a successful best 22.