I've noticed that the Outlander, is shown to be more adept, with Physical augmentation over, other abilities such as TK/etc.
This would explain why, he could take on Arcann/Vaylin as they were evidently stronger in the force at the time. And yet the Outlander managed to go toe to toe in Physical combat.
It would also explain why The outlander wasn't flung back by the Force Repulse, vaylin used, or managed to push his way through Arcann empowered Lightning. but was evidently thrown around, during the fight, with it came to the use of telekinesis,
or put on his knees by Arcann during their concluding fight.
I would conclude he is similar to Obi Wan in his use of the skill.