You gotta redefine your terms here.
Tempos are continuous runs at threshold effort/pace. The max you should be going for these in a training session is 30 min. In an ideal world, you can hold this pace in a race setting for 60 min but that's pushing it, especially as you move down the slope of being less trained. You can break these sessions up into intervals as well, by time or distance, as long as you don't go over the 30 min volume (highly trained athletes/pros can do longer sessions but you shouldn't be)
Then, there's marathon pace/half marathon pace work, which for us mere mortals should be slower than threshold pace unless you're a <60 min half runner . These runs are almost always continuous and longer in volume , as it's more of an aerobic strain rather than something that toes the line of aerobic/anaerobic like threshold work. Depending on your mileage, I'd do these at 10% of your weekly training volume.
Both threshold and marathon/half marathon pace work have their place in any distance runners plan, with the latter more often used in a base period or a build for a half/full. Threshold is just great all around.
Hopefully this helps!