[Help] We recently shelter adopted a 4-year old medium sized fixed female that shows both leash and barrier reactivity, but has a history of fine interactions with other dogs. Is this approach a good plan?

We recently shelter adopted a 4-year old medium sized fixed female that shows both leash and barrier reactivity, but has a history of fine interactions with other dogs. From walking the dog, the following seems to be true:Our neighborhood is overflowing with dogs behind fences who will bark bloody murder at our dog on sight. Sets her on whiny edge.She can be redirected with firm but gentle voices/name calling and shoving treats in her gob. Sometimes one treat, sometimes three are needed, and keeping moving.She will go into a gundog like alert posture, like this but leaning forward, tense, on her Easywalk harness when this initially happens.She will dance around, and sometimes pull on the leash to where her front paws and upper body go airborne.If a dog is behind a chain link fence (we have lots) she will often cautiously approach, and as nose to nose contact happens or is about to happen, she will suddenly start barking her head off. Sometimes the other dog does, sometimes the other dog recoils.Our dog has had some good meetings with other dogs. She seems nervous, but upon encouragement moves forward to do what seems to be normal dog meet and greets. Sometimes this ends up in barking at each other, switched in an instant.In the house, she's usually pretty lazy and calm, and is already constantly showing the dog bow "let's play!!" to the cat. Indoors, she'll growl (periodically) and sometimes bark (rarely) at random noises nearby outside. Anyone approaching the door gets a spazzed out BARK BARK BARK assault of wagging happy tails and joy that from outside would sound like a guard dog. She loves visitors once she sees them. She always warms up to strange humans right away.She seems to be a VERY, VERY submissive dog in general. VERY. Even with our cat. She seems to be accepting of being bottom of the pack?From surrender notes she used to go run around routinely off leash with a group of dogs in a fenced yard, playing fine.Previous owners hardly walked her. Like at all. Take her out till she peed and poop'd, or she would have to in the yard on a tether.I know the basics of desensitization work from reading here and online, but we don't know many people nearby with dogs, personally. We also can't afford the extra cash at the moment for a trainer. We're working on getting her calmed down on walks. She seems to recover faster now than she used to.Today was a particularly rough day: I had to walk into Petco for more food, and literally as we walked in the front doors slid open as an twenty dogs and owners marched out in a class, single file. My girl had a completely stunned freakout, but was recovering (it seemed) by the end of the line, to where I wasn't having to muscle her back.We were thinking of this idea:Reach out on Nextdoor.com for our neighborhood, to see if someone has a really good, chill, gentle dog of similar size who would be willing to do some experiments a few days a week, including trying walks together. Basically, have my dog and I sit on the edge of their lawn to start. I'd be armed to the teeth with treats. They would bring their dog out on the porch and sit down as we chat and I try to keep my dog calm, gradually having the neighbor bring their dog closer. If my dog starts to freak, the neighbor backs up. Get a couple neighbors with different dogs, try this at least daily if possible. Get to where they'll go for a walk together.Is this approach a good plan? How long should a session go before we decide, "That's it for today," if it's not working out? via /r/dogs http://ift.tt/2qNBad5