Hard full on dog plays, nothing to fear - dog walking tales ...
Many people don't take their dogs to anywhere on the weekend, because they are busy and they don't trust their dog. Their dog is aggressive or angry or fearful and it just makes any excursion hard. And the dog will stay that way their whole life if it never sees what social dogs do, away from a human yard.
We don't walk red zone dogs, but we have walked plenty of anxious dogs or dogs that need a bark muzzle just in case they do something silly that will endanger themselves, but we find that this anxiety doesn't usually last long with regular walks. That dog will need a muzzle and need to be on lead until it gets that the park is actually a fun natural place, and it will happen, but that is just the middle ground.
I have occasionally met dog owners or consults who have very strong views on about what will make their dog happiest. They rarely walk their dogs, or never walk their dogs in an off lead dog park, but they are sure about what their dog needs. And yes that is fine, but if they just went to a dog park for a few months in a row, and observed what happens, the miracle off the off lead walk, they would completely change their mind. I don't go to their work place and lecture them on how they should load the photocopier or make a website or anything else that they do, not because I don't have opinions, but because it is their day job.
If you don't trust someone to walk your dog, don't use them. But if there is a small part of you that thinks that any of this could be true - that a dog can get better by being walked in a dog park, and associating freely with its own kind ,,, then try it.
Its not rocket science but its experience. Yes each pro dog walker has their own style, but for me being present and always watching our dogs, filming the dogs (always an eye on the dogs), correcting as needed is what its about - its my day job, and I am good at it.