Tf you talking about Willis. Steph went to Davidson. NBA was taking kids straight outta HS not long ago. Several international players get drafted every year. Nobody cares where you hoop if you are good enough.
Kobe was 6-6, and had FREAKISH ATHLETICISM.
Mayo was 6-3, was almost a Kobe, and to goto 1 year of college, and went to USC.
IN GENERAL, but not always, if your 6-2.5 or less, and or are not ultimate extreme freakishly jump out of gym athleticism, and or don't go to a blue blood, or a good non WSU type program, an or don't score about, around 19 ppg, and about around 6 assist per game, and about a 39+% 3 shooter, then usually not drafted.
There are rare exceptions, but they are rare.
Jrue Holiday only scored 9 ppg, but he was about 6-5, ATHLETIC AS HELL, and went to UCLA. If Jrue was only 6-2, wasn't as athletic, or went to WSU, and only scored 9 ppg at WSU, he wouldn't have been drafted, let alone the lottery pick he was at UCLA.
Since you mentioned Steph Curry and Davidson, Steph was about 6-4, and he scored about 20 ppg, and he was about 40% from 3, and Davidson was, is a pretty good bball program, better then WSU.
If Steph Curry had been 6-1, and had only scored 17 ppg, and had only been that 6-1, 17 ppg at WSU, then he probably wouldn't have been drafted into NBA.
If Rice was 6-5, instead of 6-2.5, AND if he scored about 19 ppg, AND if he had 6 assist per game, AND if he was a 42% 3 point shooter, ALL COMBINED TOGETHER at WSU, THEN Rice would not be a fringe player.
Take Klay Thompson as a example guard compared to Rice. Almost every WSU guard that made the NBA, whether Klay, etc, was 6-6, was athletic as hell, scored about 19 ppg, instead of being under 6-6, instead of scoring under 19 ppg.
Ehlo was a exception to that generality as he had SHITTY ppg, Shitty athleticism, but was still at least 6-6, 6-7.
Usually a guard has to be at a place like UCLA, etc, if they are gonna be under 6-5, score less ppg, etc, and still make NBA, etc.