A couple things.
First off you have to weigh things heavier toward the top. How much can you dock a farm system for not having as many guys, when fully developed, that you can pick off of the waiver wire and have them produce at roughly replacement level? In most cases the top of the system is going to carry the future burden.
Secondly, this is the best depth the O's farm has had in quite some time. Are the #15-25 guys in the Red's system actually better prospects?
I think KLaw used the lack of International prospects as an excuse to question the depth and lower the ranking. I don't think he wanted to rank a system in the top 10 that didn't have an International presence on their list.