New, unexperienced people just being under the huge pressure all the time, during the tournament, because of people around them taking this as something more than simple GFs, that's why they can side block or something, but it's definitely not showing their real groupfighting skill. As I said before, it only shows their unexperiencedness.
Nowadays every member of TBE, Poosy, Snappers, many players of other GF teams don't feel the pressure anymore, tournaments are going on almost every Sunday, if you are doing it that oftenly you should be used to it, of course. That's why they are getting in some way an advantage during tourneys.
The best way to see groupfighting skill is still the league and practice matches, imo.