Only watched the sparring on the first video. I'll tell you exactly why the guy lost his semi final fight. He wasn't active enough he was backing up and only throwing single shots the other guy was moving and throwing combos and mixing up his attacks.
In the third place fight damm that other guy was huge but again same problem, he offered very little offence and backed up a lot and against a guy that big it's not a good strategy. The big guy didn't look that great to me he looked clumsy your guy should've got on the inside and looked to land punches to negate his reach