I have filmed three BJJ competitions for my team so far. I find it more rewarding and much simpler than taking photos. I have used a smartphone as a camera and a tripod for smooth panning. For the tripod, I have used either two-way fluid head (video head) or three-way pan head.
I have thought about filming with DSLR but I would need expensive and 28-70 mm light lens which I do not have and the complexity of the whole filming process would also increase.
This is the video I filmed at Estonian Nogi Championships using iPhone SE3. You can see the wide angle, image stabilization as well as the quality of the digital zoom.