I recall speaking to a bike shop owner who was in the business back then, and he said that prices were escalating quickly in that time frame, and that many bike manufacturers were looking for ways to cut costs by downgrading some of the components. I'm not quite sure about interpreting serial numbers on Fujis, but despite having newer components, bike B may be older, and thus have better stuff on it - and bike A has slightly older, and probably down a notch components on it.

I'm not sure what the difference between 212 and 414 tubing is though.

Where's T-Mar when you need him.