The problem with TW is that it is the most time-consuming event for active participants. You can take a whole day off work for the attack phase if you want to play it properly. And for such a commitment, the rewards at the highest level are completely ridiculous and haven't been up to date for years. The result is sandbagging, whether conscious or unconscious, it doesn't matter. The game mode is broken.
Replace it with something less time-consuming and rewards that are also interesting for guilds with 500+ GP. How about a special character that can only be obtained in small pieces through TW victories? Sandbagging would come to an end immediately.