that video shows exactly what to do lol. Have a decoy tackler which fui runs to and have another who runs in from an angle. If you hit them high, momentum just takes it's course, the guy lands flat on his back because you stop his top part of the body, yet the lower half keeps moving forward = he falls on his arse lol
this is why SBW's shoulder barge always worked when it connected. He hit high, and stoped the upper momentum whilst the lower body continued to move forward.
Knowing FUi FUi Woy Woy he will just run straight and fast, he will try to barge through, all you need is a large forward to run on an angle into him and hit high with a shoulder or forearm hit