so soldiers anywhere from 1 year to... several? ok, i can believe that some would have a lot of stamina, but I'd say the majority of Seers would be from 1 year to 3 years. I say this because I'd guess lifespan as a medieval soldier isn't very high. so some added stamina, but not too much.
Correct me if I'm wrong, but if you're the squire and you see the Seer that managed to get out of the circle stop running, you're going to chase him. You're faster and tire less because of Stormlight, so they'll get tired and you can pick them off. The run for 12 seconds than rest for 48 idea wouldn't work.