I grew up with Shelties. Their job was herding me while I was out playing. Yep, that's right. I had canine babysitter. He kept me from running out of the yard and into traffic. We have old family videos of it. I was very very young. My mother wasn't out there with us. She'd just send me out to play---with the dog as my babysitter.
If you think that's weird, keep in mind that she grew up with shelties who had all kinds of responsibilities without supervision. He'd walk her to the bus stop a mile away from the house, sit with her until she got on the bus, and he'd be waiting for her when the bus returned in the afternoon. He took the cows to the far pasture in the morning on his own without being told, and he brought them back in the early evening without being told. All of his jobs were done on perfect schedule, like clockwork, without being instructed.
So, my mom knew a thing or two about the capabilities of Shelties.