The point of the cue (the “name”) is to form an association between the cue word and the behavior. The goal is for the cue to trigger the behavior. It doesn’t make sense to form an association with an imperfect behavior, so until the dog performs the behavior you want, attaching a cue to an imperfect behavior will result in the dog performing that imperfect behavior in response to the cue. In other words, “The behavior you name is the behavior you get.”
If, after you cue “sit” the dog hesitates for 4 seconds, sits, gets praise and a treat means the dog is learning that “sit” means “wait 4 seconds, then sit”.
Learning generally happens faster with fewer distractions. Whichever of you is saying “sit, sit, sit” may not consider that a distraction, but it can be. At best, it is meaningless. At worst, it’s a distraction that can impede learning. From another perspective, repeating “sit-sit-sit-sit-sit” could even constitute negative reinforcement — nagging that stops when the dog sits.
Pavlov’s experiments demonstrated that the association between the cue and behavior is formed only when the bell,
light, “sit” or any other cue **precedes** the behavior — not during and not after the behavior. In other words, it isn’t helpful for learning to say “sit” after the dog has already sat (“Good sit”).
Dogs learn cue associations when the cue is given just before the dog begins to perform the behavior. Then it takes 20-50 repetitions for the association to be formed. The bottom line, when you are 95% certain that the next behavior the dog is going to perform is the behavior you want, say the cue, verbally praise or click, deliver the treat to reset the behavior, say the cue, praise or click, treat to reset the behavior, etc.