i have argued this before, but i don't think any walk on should be worse than a 330 to 350 rated player. here's my reasoning for this:
for 6 years, i used to work part time at a rec center. we often had college basketball players in playing pick-up games; you would rarely see a DI or the occasional DII player but we had a few DIII players (most from a DIII team in this game, btw) who lived in the area who would play often.
if i had a break or if they needed another body to run a game, i would sometimes play with them. as an aside, i played only one season of organized basketball my entire life, but i am in pretty good shape and know enough about the game. on these few attributes alone, i could hang with the DIII guys. there was a definitely skill level difference, but it's not that noticeable.
my point is this - if someone in decent physical condition who plays basketball a bit can nearly hang with DIII guys, a walk-on would be BETTER than me on a team of any level. even a bad walk-on playing for a DIII team in this game should not be any worse than a 330ish rated player. it is laughable the walk-ons could have a rating as poor as 194. even a scrub like me would probably merit a rating in the low 300s.