61% of 5* are drafted, 23% of 4*, 5.1% of 3*, and 0.5% of 2 star or lower
So a 4 star is about 4.5x more likely to be drafted than a 3 star. And a 3 star is 10x more likely than an unrated guy.
That's looking at the player, but let's look at the teams.
The team with the better rated recruits wins 73% of the time. Not a guarantee by any stretch but a pretty solid indicator that incoming talent matters.