Please refer to the following video: as can be seen, the smaller man wins. What technique does he use? Where can I find more information about it? Generally, are there any additional techniques/ drills that smaller person can use against stronger/bigger opponent?
On youtube, this is titled Jouko Salomäki vs. Hans Fell. In this match, you should notice that there is a huge skill disparity between the smaller man and the bigger man. The bigger man is uncomfortable and never actually produces an attack.
There are no magic techniques that will make small people win against big people. As I pointed out in my answer to your other question, you need to train techniques well to get them to work against bigger opponents. In any martial art, you should be training with the mindset that your opponents are bigger and stronger. If you understand how to make techniques work on bigger and stronger opponents, it is straightforward to apply them to equal-sized or smaller opponents.
Here is the brief analysis of the wrestling techniques in the video:
- ~18 sec single leg takedown. This is one of the first attacks you learn in wrestling. There are many variations.
- ~30 sec gut wrench
- ~56 sec To me this looks like a fireman's carry attempt.
- ~60 sec front headlock roll
What are the best techniques to use against opponents who are bigger and stronger? The techniques you are good at.