i know what you mean. you are right. but all threads about tempo runs end up in hairsplitting.
tempo runs are bread and butter, well proven.
just my view: i doubt that sthg. like an "american tempo" exists. there are a few ways to define a tempo run. personally speaking, it´s sthg. in the range of tempo runs and threshold runs à la jack daniels.
you may laugh but i prefer the furman/first-style to keep it simple: short tempo of 2-4miles (10k race pace); mid tempo of 4-6 miles (10k race pace plus 10s per km); long tempo of 7-14 or 15 miles (10k race pace plus 15-20s per km). these tempos are great producers of aerobic fitness.
intervals are sthg. different (way faster!).