@Osaka I heard they dropped the "minimum"-rule from a trusted source, but that was half a year ago. They sounded quite confident that that was the way forward (since it also made it easier to catch users who plagiarized their uploads) so I'd expect it's still implemented that way.
Osaka
You have to be scouted yourself before you can scout anyone :)
See this for more info - https://www.newgrounds.com/wiki/help-information/content-submission/scouting
(If you're already scouted, you can read that guide)
If you're a scouted artist, you can click on any of their submitted artwork/audio (they must have a minimum of four) and press the scout button that pops up on the top left corner. The site will give you a confirmation check and the one you scouted will receive the scout offer from you which they can either accept or decline.