Or other teams overvalue LA prospects early in their careers?
Caba seems like a solid but risky (to succeed, he has to fill out and develop gap power) prospect, far more risky than say Crawford.
The difference between the draft and LA is in both cases you can shift money between players (and the cap on LA money operates similar to the draft in that you only get one or two "top" picks) is information. You're drafting 18 year old HS players or 22 year old college players v what is essentially 15 year olds for the top guys and 16 for everyone else. Which is why more LA "late picks" surprise than MLB later draft picks.
Because there's far more risk in LA signings, you should probably avoid overpaying at the top unless there's a "Sure" thing, and how many LA prospects can be considered high probability to succeed, compared to the 1st rd of the ML draft? This variability in results may make it more efficient to spread money around.
I hope the Phillies have sat down and figured out the odds and the optimal strategy, instead of relying on scouts' gut feelings.