On the other hand, I don't think that tobacco has the same variance from year to year as grapes. Grapes, and thus the resulting wine, are very sensitive to meteorological conditions - temperature, rain, constant sunlight, constant soil minerals, etc. It may be an ignorant opinion, but I think tobacco is not as sensitive in this regard, therefore the quality of the harvest and the pipe tobacco is more constant from year to year. This is probably the reason why I don't put an emphasis on aging, myself.
There are single crop tobaccos out there. McCrannies and McClelland's Christmas Cheer. There are others, but my old brain is drawing a blank at the moment.
You are right about most blends. Most are like blended drinks or wines. They blend the tobaccos and case them. The companies do this to keep from varying to much from year to year, for exactly the reason that tobacco does change significantly from year to year because of environmental conditions.
However, even the blended, cased tobaccos do change when aged also. Not as significant or as predicted as a single crop. But, it is enough to keep me setting some things back.
On the other hand, some tobaccos that are fantastic to begin with, just don't seem to age at all. I have several pounds of PS LTF with four to five years on them that are exactly the same as the day I jarred them up. It's fantastic stuff, but there is something (whether it's the cavendish process or PG's) that keeps this stuff from benefiting the same as all of my other tobaccos. Maybe it is just slower to progress or something. Maybe it needs twenty years to get the same benefit as a 5100 Red Cake.
So, as you learn some things about blends, as with wines, you can start to make predictions, take risks, and get some quality aged blends.
BTW - to the OP, thinking about the age, and comparing ages of the same blend is a passion of mine in this hobby. So, yes.