



Regarding the punch, if we consider the specifics:

First, he cheated (I think it would have been better if he 'feinted', if you want him to use deception, or he can actually break from said 'fox' stereotype and play this fairly...and honorably). This allowed him to come closer to the rhino. So, in order for the punch to hit him hard, he would have to accelerate his punch to a great extent within the short distance between him and the rhino (which is nearly impossible) or he has to be a lot more stronger than he is otherwise, so that the punch renders him 'unconscious'.





I think in this case, it would have been better if he just used the same tactic as Judy did, if he pulled back against the rope and slingshoted swiftly towards the rhino with an even stronger punch/a punch to the rhino's punching arm (that would definitely work even with less arm strength) and it'll still make sense if he gets his hand fractured from that.





Unless, he has been to the gym before this, in which case your head canon might make more sense than it it did before.





And this is of course, one of many possible situations (it shouldn't be that Nick passing this on his first trial should be inevitable, or even be the most likely outcome; even though the trick he pulled off can increase his probability of winning to a great extent.)



Regarding his skill set, he does have good speed (usually taking head starts before hand though) and a few athletic qualities (as mentioned numerous times), his strength...has been cartoonishly exaggerated at one point...and it isn't shown much later on. He isn't at the peak of his physical condition (as it comes off from the comics.)



Doesn't help that others may have not considered the punch speed to be a factor while you are telling it to me, and most other people think that him growing up on streets results in him being good at fighting, which as I also said depends on how many physical confrontations he had been with others. Doesn't help that during the fight scenes with the sheep minions he didn't really fight anyone, Judy did, while he tried to control the train somehow

He did take a head start at that time, after which he got tired quickly. Idk, if that'll work with his punches, given in a short distance.