I didn't know Parraz had a year in college. But he illustrates the rapid improvement possible in young guys. Per the baseball cube, his only years listed were as follows:
04 44/24 .244/.349/.400
05 46/12 .259/.307/.365
06 26/19 .325/.427/.500
He actually regressed his second year, but has taken a gigantic jump this year.
For Ramirez, I've only seen the batting average data as I don't know where to find comparable data, but I'm pretty sure he would also illustrate a sudden leap forward in his forth year.
Anyways, back to your question about scouting vs development. My opinion in regard to hitting is that the skills needed to become a good hitter are pretty much inate. In other words, if the young man doesn't have natural hitting skills, he is unlikely to develop into a major league hitter. If he is a natural and emotionally matures, he has a chance to rise to the top, in any organization.
So, if you conclude that the organization is poor in hitting, my opinion is the problem lies more with scouting, since I doubt an organization can teach poor hitters to become major league hitters. Pitching seems totally different. I suspect it is equal parts scouting and development.
All in all, someone more knowledgable than I am can probably make a good argument and provide some insight into the general development vs. scouting question. IMO, it is a very interesting topic.