Your advice is well taken. If ever there's a time to load up on Type A's, that would be it.
As to why I'd want to do that, it's my experience with 20 mil College drafts for my other team. Due to the amount of prospects I see, I can get useful minor league players down at pick 6,7,8. In HS drafts I usually see only about 120-140 prospects even worth spending bonus money on. The top end of the drafts is the same, but the depth is totally different. Plus the longer wait for prospects to be ML ready. I just feel like I have a higher comfort level with College drafts, that's why I'd even think about this.
However, one of my reasons for posting this is that while this four-season transition has been proposed a few times in these forums, I don't know that anyone's actually done it. If no one has, that's an answer in itself.