Hi,
The word “vigilante” matches either the title, content or the terms of many products, that’s why it shows over 420 additional matches. I have checked the back-end woocommerce product search, and the number appears to be correct: http://i.imgur.com/I81Qxmv.png
If you want more strict results and less suggestions, you can turn on the exact matching: http://i.imgur.com/EEbuSzA.png
It will display less suggestions, but they might be less relevant though.
You are looking for the limits settings, on the General Options -> Limits panel: http://i.imgur.com/hNJoU53.png
Change that to 4 or 8 and the results count will change 🙂
There is a whole chapter in the documentation I recommend to read to maximize performance and minimize server load: https://goo.gl/Rn6lG6