I received an email from Triumph yesterday about this. Going up against the 4 Japanese companies, KTM, Husqvarna, and some of the smaller brands, to be competitive I think they've got some rough roads ahead, no pun intended.
LINK: Motocross and Enduro
The Triumph scramblers were not very good at moto cross, ISDT, enduro, or cross country races. Cross country in the mountains of BC, would be a lot different to Kansas.
Bultaco, Husqvarna, CZ, Montessa, Maico and many others were the bikes to ride. The British used 4 strokes and did well a long time ago. Any reading about Jeff Smith will reveal much. Lighter weight two strokes smoked ( hee hee ) the British four strokes as the MX bikes developed. Ask Porky about the CZ. Was also the first MX bike I rode at a track in Portland OR.
The new Triumph has done well at copying and borrowing design ideas from elsewhere. Plus designing their own.
My Trophy 900 has fairings from Italy, a Kawasaki copy gear box, brakes, gas cap, ignition switch, and other bits that are the same as on my SV1000 Suzuki.
Back to the high pipe Triumph. The pipes caused your leg to stick out at a silly angle. Dumb system. A bike like Steve rode, would be useless at any serious off road riding. My 125 Rickman with a Sachs motor would smoke it in the rough terrain. I once lined up in the ditch, with 142 other keen riders. First part of the race, was up the side of a steep hill / big bump mountain. I crashed about six times getting to the top. Fast forward, a sage brush removed my shifter. 39 finished. UK