I have never played this way. Although I do understand the 'circle about' mentality, I have never seen two armies start individual dance around each other in any depiction, just clash and hack at each other. I know in SBG that this allows (is being use for) people to 'trap' a person who would normally not be trapped (or trappable) because he has his mate nearby that would take on the guy trying to get round the flank... if you are going to cite 'realistic' circling about, then the realistic guy next to the combat is going to slit the guys throat when his back is to him.
I have always played that the first guy has to directly charge with shortest direct route once he enters the control zone. Then and only then has the control zone been neutralized. Afterward, other friendless of either side can pass through the combatant control zones, thus allowing trapping or getting past to obtain an objective (or board edge).
I think this 'purposeful misinterpretation of the rules' being done allows too many trapped combats (which is why people who use it want to keep using it and make it legal). I think that even if GW gave blessing allowing it, I would still not play that way and follow the rule to the letter and declare that with my opponents in advance.
It is nice that people like to use the phrase 'adding tactics' to the game, but enforcing the rule the other way adds tactics just as much since the opponent will have to think how best to neutralize control zones to be able to slip past to either trap, or get to an objective. Wheeling around a model is not adding a tactic in my eye, it is taking them away and allowing free-for-all pile ups on models. IMO It is not a game changer, but my opinion is what it is.