Plus they complained when the CMCs went off to have fun at the fair instead of sticking around to keep giving them advice. Evidently, that was all just a ham-fisted means of reinforcing the episode's intended moral.
It was implied that Biscuit and Spur lived within walking distance of the fairgrounds - the [claimed] issue with the CMCs needing a chaperone was for taking the train from Ponyville to Appleoosa, never mind that they had successfully taken the train by themselves in "For Whom the Sweetie Belle Tolls" and "The Last Crusade".
Plus Biscuit and Spur were revealed to be older than the CMCs, which combined with the Ferris wheel scene equals strong evidence that this episode was originally meant to take place in an earlier season. Back in Season 7, the Crusaders were running a children's day camp with no adult oversight. And here, we're to believe that if not for being magically aged up, they'd be too young to ride a humble Ferris wheel? Does not compute.