I'm sure some tough old broad puppy can overcome a little dragging. But lots of puppies are insecure and more sensative, unsure of what the heck we're asking of them and just completely naive. Usually, I wouldn't recommend dragging at all, putting any tension in the leash while puppy is still getting use to it. Its all new. I actually start puppies out with no collar and no leash at all in a safe area, of course. (fenced) I make it into a game for the pup to come along with me, using a silly toy, maybe a squeeky one, some yummy, tiny treats every couple of steps (at first)...running a little, patting my thigh. The pup will tend to love this game and when he is doing it regularily with enticement, you can start sticking in a cue, "let's go" in a happy, cheery voice and lots of praise and treats along the way. You can make turns and stop and go again. You can do this for a few days until the pup is really onto this game of coming along beside you. (aproximately beside you is good enough for now)
Meanwhile, in the house when you're just chillin' you can let the pup drag a leash around for a little while, but be sure to supervise constantly so he doesn't get strangled or tangled. LOL. Pick up the leash and let him go where he wants with you going with him. Then try (in the house) going where you want to, again enticing him the same way you did when you were playing the no-leash game. Don't create tension in the leash. Use your happy voice, patting your thigh, a toy and treats as he comes along with you from room to room.
Then try out in your yard. Don't try walking down the street on a long walk yet. In a week or so, he'll be walking happily along your side. You must reinforce what you like and reinforce every few steps with what HE likes best of all. It has to be better than anything else he may be wanting to do. Later you will spread out the treats so he has to take more "nice" steps to get the treat. But at this point, he is still guessing what it is you want him to do, so to make it clear, he has to be rewarded often. Build up that bank account of reinforcements until he makes a clear association of what it is he's doing which is getting him the thing he loves.
We may know what we want, but they have to guess for a while. It could be to him at first to mean some other behavior he's is doing at the same time as he's walking along.
Am I getting a treat because I just wagged my tail? Should I wag my tail again? Am I getting a treat because I turned my head sideways? He doesn't know at first that its the walking along side you that hes being rewarded for for sure. He's still guessing. So, that is why many repititions are needed with reinforcements which come immediately with his "good" behavior.
Don't do this for long periods...5-10 minutes 2-3 times a day is fine. Start where there are no significant distractions...your house, your yard. Be sure to end on a good note with something he does well. Quit while you're ahead. If he does some very good walking, even for 3 minutes, stop. Give him a party and come back another time. There's nothing worse than risking his doing a crappy job and then ending the session or trying and trying to get him good again. It can make him sour to it. Leave it with him wanting more.
There's no need to get into a power struggle or an argument about who's boss. Once you start doing that, the dog is more apt to learn that everything is a struggle and he may as well concede. He does things to avoid "corrections" rather than becoming a willing participant. The nature of dogs and humans and their bond is
not the nature of wolves with wolves. Our dogs' ancestors lived in the outskirts of primative villages where they scavenged alongside eachother, but not as a pack. There is no need for a pack when food is prevelent. Those neolithic people tolerated them but were not very involved with them. This was the niche they found and from there is where our dogs evolved.
LOL....I guess I had time to write a lot after all. I had to make a phone call and thought I'd be on for ages, but not so.