Actually, there seems to be two schools of thought by experts on this subject. Personally, I have to say that I don't buy the hierarchy stuff to the
extent that a lot of people do on account of these being domestic dogs who do not live in the wild.
So, for me, in my household of multiple dogs (and I've had multiple dogs for a long while) I do not reward behavior I don't want in my home. And so far, I've never had problems with my dogs in this way. There may have been a hint or two of a potential problem coming along, but I think I got the message across.
Lyric was a pesty puppy too and would irritate Jose. Chuli was so small and a girl, so he didn't seem to bother with her. But his pestiness was that he was trying to instigate play and getting pushy about it. Jose would give a little lip curl or growl. Jose, lots of times does like to play, but not when he's trying to nap. LOL. Lyric never growled back. It was as if he was oblivious that Jose was irritated. However, I would definitely step in and not allow him to continue pushing Jose's buttons. So, I'd step between and move Lyric off, give him some other thing to do where he could be reinforced, like come into the adjacent room and play with me with a rope toy after a few seconds. I'd interrupt him quickly and distract him. When I saw him ever standing near Jose, but not being pushy, being calm, I'd give him a treat and cue word, "leave it" or....if Jose did feel like playing, remind Lyric, "gentle." In other words, I made it more beneficial to Lyric to "leave it" more fun, more tasty than to continue on the path he was headed.
All behavior is contingent on consequences. The consequence of Lyric being pushy was that he never got reinforced (very much) for following through and getting the fun he thought he was about to get by bugging Jose because it was interrupted. The consequence of leaving Jose and dropping the idea of getting too rough and pushy was that he got to play rough with me with a rope toy (tug)...his favorite and he'd even get a high value treat to boot. Soon, he associated the word, "leave it" in that context too and when he heard that cue, he pretty much automatically would leave it.
My two boys are great buddies most all the time. Lyric is a lot more mature now too. But he does occassionally do that play stalking thing and I definitely interrupt it. He's playing but it clearly bothers Jose. I tell Lyric, "eh-eh! Leave it!" And if he doesn't (sometimes he doesn't) I step in and herd him off. If Lyric and Toker (bigger dog) want to play that way, fine. But I won't let that instinct to stalk, even though it's play... get going with my little dog.
That said, I think Ripley needs a lesson in some manners and if you let Dakota teach him, especially if they're not that fond of eachother, something bad could happen.
Ripley started jumping and yapping in an attempt to get a treat. Dakota started doing the lip curl and I distracted him with a down command. Ripley bounced right on top of Dakota, and Dakota just silently snapped at Ripley
How long has Ripley been jumping and yapping in an attempt to get a treat? What do you do when he does this? I wouldn't give him a treat until he sits quietly. Something has been reinforcing this behavior. Before Dakota gets to his threhold of frustration, that would be my cue to move Ripley away with a command, ("away"? or something) and make it well worth his while to put some distance between himself and Dakota and to follow your command. The trick is to interrupt it BEFORE Ripley gets reinforced by thinking he's succeeded at accomplishing what he's setting out to do, at the first sign of intention, the first muscle contraction. LOL.
I would not leave those two together unattended when you're not there. It sounds potentially dangerous. One bite from Dakota, one incident of poor guaging of his bite pressure and Ripley could be dead. It doesn't sound like they have settled into your system which IMO you set up for them, being the "Mom." That's my philosophy rather than letting the dogs fight it out. Dog squabbling, fighting is not allowed in my house. And I'll use verbal "corrections" too. But I make sure to reinforce the "nice" behavior. It's worked well for me this way. I have a very rare incident anymore where I have to do anything at all. But there is a little difference in that my two boys do like eachother and will play together, go exploring up in the woods together. The unwanted behavior never seems to happen when they're busy and "on a mission" together to chase a squirrel. They seem to cooperate together. It's more when we're inside or if they're bored. I do watch it with the high value toys etc, just in case....seperate them when they eat....just basically manage the environment so stuff doesn't tend to come up. I leave nothing too fun for them when I go away and they just sleep. (I can tell when I come home by the warm cushions....4 of them. LOL)
I've never seperated them when no one was home before, except when Lyric was a he!! raiser. But I'm thinking I'm going to start doing that. Lyric just turned 3. He's more mature. He's never shown one iota of aggressiveness, has the most incredible tolerance for things and they all get along great. But, something could come up and he could react differently than he ever has before. That's always a possibility. The Chi's tend to go in their crate a lot of the time anyhow, so they won't mind being seperated. Those two can definitely be together. They're madly in love. They're best friends in the whole world. The big dogs sleep on the couches, so I might have to put one in my room, bring water in there. Uggg, kind of a hassle.
I hope things will get fixed up for you. What does your trainer say? Did you ask her? I do know people have different ideas on this. I just know what has worked for me. I've had no significant problems that way. Ripley does sound more hyper than my dogs and I realize it's harder to "get through" to him. Just be careful. He is a tiny little dude.