No, you're not overthinking it. For example, component flavors vary from year to year due to varying weather patterns. Manufacturers deal with this in a variety of ways. One way is to compose the blends from components mixed from several years of crops. This reduces the year to year variations.Is there any rule of thumb to just give newly purchased tins at least a few months to marry a bit? I have ordered some tins that were packaged within two months of getting them and they seemed like they could use some rounding off of flavor. Or maybe I am just over thinking it.
Generally, the components have done a bit of marrying before being tinned and offered for sale. But a lot of smokers like what some extra aging brings. Most of the effects of aging happen within the first 5 years, but six months to a year of letting the tin sit before opening can increase marrying of flavors.