I applaud you for recognizing the behavior for what it is - so many are not aware of what a "body standover" is and means.
According to most behaviorists I have spoken to, including Patricia McConnell, a body standover is one of THE most offensive gestures in the canine world. Dogs are individuals and how each one responds to offensive acts by others varies and runs the gamut, but for the dog who takes this for the status seeking motive that it is, it could spell big trouble and is best to always prevent it. One of my girls, Gracie is a great example of a sweet natured and dog social dog but there are two things she will NOT tolerate: being mounted or taking a body standover.
The best thing you can do is to prevent the set-up and never allow him to cock his head over the neck/back of another - either by pulling him back with the leash, or taking him by the collar (if offleash) and gently turning him away while teaching a "cue" such as "leave it", "off", or "look at me". Once he knows the cue, you should be able to verbally redirect him. To best teach the cue, use high reward food treats to lure him off of things while saying the cue word.
My dogs all know "look at me" for example and I find this to be the single best command we have. It is super easy to teach - every time my dog looks at me, I clicked and treated. After several times of looking at me, and recognizing the pattern that "I get a reward when I look at her" - I started saying the cue "look at me" and re-inforced it. It took no time for them to learn the cue and now I can control any distraction with the cue or prevent my girls from focusing on a dog with crude social skills (who is about to do something offensive and for which I am trying to avoid having anyone get offended).
If you start now, you should have no trouble teaching this command and controlling the status seeking. Last case scenario, getting yelled at by dogs he offends may be the best teaching as well, as long as no one means harm and is focused on just verbally discplining.