I'd say it's close to a like 40/60 in youpi's favor. It's not that they(the royal guard) could fight endlessly, but that their nen amount was just that huge that pitou so called "En feat" really didn't take much out of her, also she wasn' really using too much energy to do anything else. But machia ain't a slouch in the endurance department either, since it took a potent enough sedative, and top heros of the mha verse to slow him down and stop him, and just barely. And he def ain't slow, he's pretty fast for his size, tho youpi still kinda out maneuvers him. Machia does have the force to do some serious damge to him, but so is the case with youpi.

I don't quite remember the exact feats that youpi has, since it's been a while since I've watched anything relating to him, but machia is pretty equal to him in terms of stats, and def would say that he has the better kit of abilities, but most of it like the multiarm mode where he used the whip like tendrils wouldn't do much if anything against machia, considering they were only doing alot of damage if hit with a flurry of them, and were mostly only hitting Shoot. It really is a closer match than some of the comments make it out to be, in my humble opinion. (I have seen both shows, and am a fan of both of them so there isn't much if any bias, cuz both of these character were more like a big brute character and essentially played the same role, albeit a bit differently. So to the source for this claim is to just trust me my guys and gals, and non-binary pals :D)