As it turned out, Jason's unreasonable power, despite being weaker, was able to defeat Thor's unreasonable power. The fight also let people know another weakness of the giant red golem.
This weakness is that the red giant's senses weren't as good as those of a cultivator at the third mortal coil. There are many other weaknesses such as slow reaction times, but very few people can take advantage of these weaknesses even if they knew about them.
The fighting fields for the outer sect competition didn't take place in one single location. The fights took place in the fighting fields in the mountains all over the outer sect.
This was because there were just too many people competing. Instead of wasting time by using a single location to serve half a million competitors, it was better to spread the fights all over the outer sect.