At the same time, most of those martial arts don't fair very well in combat sports. Technique is extremely important, no doubt, but when the difference in strength and size is such that you're basically a child fighting an adult in his prime, you're going to have some serious issues. When people state technique is more important than size, it seems like they're assuming the larger, stronger person has zero skill. This is the case in movies from the 80s starring Patrick Swayze, but both in the military and combat sports, this is rarely the case. If they have similar skill levels, the bigger guy is probably going to win unless he has terrible cardio and gasses out. Be it grappling, striking or whatever, a bigger guy's hits are going to do significantly more damage. Case in point, Brock Lesnar vs. Frank Mir. Frank Mir is a great fighter (arguably better than Lesnar), but Lesnar was such that it was like fighting the Juggernaut. After that loss, Mir retooled his game plan, got significantly stronger...and then lost again. Because Lesnar's technique improved, and he still retained his physical advantage. That happens a lot. At the same time, you'll have someone like Fedor have a joke fight like he did against Hong Man Choi (
https://www.youtube.com/watch?v=P3QzX1ZadJM), and just completely destroy him. Why? Though Choi was certainly taller, he completely lacked skill, had always relied on his natural strength and reach advantage, and just wasn't a good fighter. Fedor, on the other hand, was a monster. He was powerful, he was very fast for his size, he was patient and he was masterful in his technique.
So yeah, technique is important in individual combat, but if your punches are glancing off some dude, or if you're trying to put him in an arm lock but can't close it because he's manhandling you, your technique isn't going to do much.