Underclassmen competing with more accomplished Upperclassmen in workouts is very, very common. In fact, it's the norm. And annoying for the Upperclassmen.
It usually doesn't immediately translate into race results because you're actually trying harder than they are in workouts. Also, you need time to recover, so racing on easy days may feel good, but ultimately hurts your development.
On a positive note, I find that many of the guys that do this ultimately end up running well but only after they learn the lesson to not race on easy days. They have the right attitude and desire to be good, which is 90% of the battle (along with talent, obviously).
So, my advice is to not obsess over beating your teammates in workouts. Take the easy days easy. Train consistently. Eat well. Sleep well. You will improve and probably surpass your teammates.
Good luck!