Over on the SJG Forums, a question was asked about Tug of War.
Seems like Technical Grappling can handle this pretty easily.
First, combine all the Basic Lifts of all the characters on each side, using their Trained ST if they have any training in Tug-of-War specifically. I’d say use the Fast progression if you have such sport-specific training.
Convert this to an aggregate ST score.
One, two, three . . . Go! Both start pulling simultaneously, rolling CP on each other.
Then just use Shoving People Around (Martial Arts, p. 118 and TG, p. 25) to move the center of the rope as many yards (usually a couple) to win, or even try and perform a Takedown.
Fairly straight-forward, I think.