If we're only talking about standart versions and not power ups (in which case OT wins easily); Knight Optimus does seem to have less stamina. In the Bumblebee fight scene, when he was pinned to the ground by Bee, he couldn't get up for 15 second and in return ate a hammer to the face (yes Cade was on top of him but Optimus was bloodlusted and was still in trance so I don't think it was because of Cade AND he was visibly trying to get up but failed). He was also pinned by Lockdown's projectiles and the sword going through his chest but I think this can be excused. Remember, Lockdown's projectile was made of a very durable material and was traveling at high speed , it's understandable that it might have messed Prime up. In both instances, the objects went through his inner workings. We've never seen OT Prime's chest getting pierced that badly (only in one instance in Forest Battle before his death, he was still moving when he was stabbed by Megatron but so was Knight Prime in AOE when he was stabbed by Lockdown). Skill wise, they're the same, both go through Decepticons like butter (I don't think a few years of practice makes much of a difference, especially considering that they're thousands of years old.) I mean, Knight Optimus does have that flying ability but he doesn't use it that often, I don't think that's a game changer. Firepower wise, AOE Optimus' gun seemed kinda weak, LK Prime's (in full power) could push Bumblebee off when its projectile exploded near him. LK gun in its rapid fire mode was pretty weak and only seemed to be an annoyance to Bumblebee. On the other hand, Movie one Optimus' weapon teared off pieces from Megatron's armor, in ROTF, it threw Megatron, a multi ton metal man, through a wall. OT Prime's firepower seems stronger. So yes, OT likely wins if we consider them different individuals and go off simply by their showings. Well in some stories, traveling back in time merely creates alternate universes. Meaning these Primes might be their alternate universe selves instead of really really being the same guy. It's unknown which rule Bayverse would follow in terms of time travel though (if it were to happen, it would probably be the way you describe it though).