You can flame me if you like. My flame suit composed of a lifetime of being around dogs, both personally and professionally, is on.
I do not let my dogs make "friends" with any other strange dog on a leash. They do not need any "friends" or exposure to any animal where the heath status and vaccinations are unknown.
Further, if you allow two dogs to meet, nose to nose, within a short period of time one of them will often start to assert dominance, which often will lead to a dog fight. I am walking my dogs to relax, not to break up dog fights.
So, no hard feelings, I'm sure your dogs are great, but we do not need a "meet and greet."