Miko must be the strangest dog alive. He is a huge tugger. He loves to tug tugh tug. More so than Koji (heck, Miko tugs Koji around). He'll put his entire body into tugging and absolutely loves it (I love when he starts to growl). But when it comes to biting, he doesn't ever ever bite. No matter how rough I play or how much he bites at me, if he even bites anything, his bite immediately softens up. (but then, he also loves to play fetch, so maybe he is a strange dog). Hmm...so maybe he'd be a good herding dog. He can pull at their tails, but will never harm them. hehehe.
Koji on the other hand isn't a big tugger, but he'll take your fingers off if you give him food. He also will bite you if you play too rough. No bite control. Still haven't been able to fix it.
Maybe my dogs are just broken Shelties?
Just some insights into my dogs:
Ember has no/little prey drive or herding drive but she has a huge food drive. She'll not bite down unless its food and then she'll take your fingers off if your not careful. She knows better but you need to remind her. She doesn't need the chase part to became interested in a prey item so I don't know if food drive is always the same as prey drive.
Ember needed alot of bite inhibition training with food but not much with people.
Justice is a natural retriever and has good not great herding instict. He would chase anything and pick up anything as even a small pup and bring it back to you. At first, he would grab a tug hard and try to wrestle it away from you. I worked hard on bite inhibition and release the retrieved items so I think his lack of tugging is learned. Now he will bite down some on a tug but if you get too forceful he lets go. He also will bite fingers if not careful but not as bad as Ember despite all the bite training I did. I think if I hadn't done so much obedience with him before starting agility and trying to get him to tug he would have been really good at it. I would say he has the highest prey drive of my dogs and has actually caught and killed a rabbit in my backyard.
Diva has great herding drive, the best any of my dogs. She would spend all day gathering and pushing around other animals and people if they let her. She loves the chase would lightly nip the back of your legs and has good natural retrieving skills but it is the motion that does it for her. She is a ball fiend. She didn't always bring back what is thrown but always chases it. At first if it wasn't moving she wasn't interested. At first she would grab the tug but not bite down hard. I did nothing to discourage her from biting down on a dumbbell, tug or tennis ball. Actually I had to teach her to hold a dumbbell and bite down using a clicker. I never forced her to give up an item like Justice, I just stopped playing and she'd drop it. It didn't take long as it was rewarding. When we started agility they wanted us to use a tug which she got really good at but when we started running with it she focused on my legs and chasing me then at the tug. She still has problems when I'm moving but if I'm standing still she is a good tugger. I did no bite inhibition with her at all and she has the softiest mouth and never gets grabby with food. She chases rabbits and such but I don't think she'd know what to do with one if she caught it.
In contrast, Jazz was a JRT/beagle. Huge Prey drive. If she chased something it was with one purpose to bite it and kill it. The only thing she didn't chase was cats because the first cat she saw was Stretch, who was spawn of the devil and she boxed her in the eye several times instead of running. She loved tug toys would hang from them ,growl and ,spin like an alligator. She charged my roomates chichilla hutch once and hit it with her head and dented it trying to get the small furry inside. Picture Velociraptor in Jurassic Park.

Loved frisbee and chasing balls. I worked really hard on her bite inhibition, she had the softness mouth and once she got her toenail stuck in a kennel door and bit me 5 times before I got her loose and I didn't have a mark on my arm. So bite inhibition alone doesn't cause a dog not to tug or not..