I've never seen a Virginia blend that didn't transform with a year in the jar, as long as you know what variety of leaf you're buying the rest is practically be irrelevant.
If you really want to do it like the big blending houses then maybe try doing just that, blend together leaves from multiple years to gain more consistency.
As long as the wholesaler doesn't start buying crap I doubt that blending different growing seasons would make much of a difference though.
I'm sorry but you're just speculating from nothing. Spend the next year buying and blending raw leaf and then we'll talk.