A volatile situation like that would have to be witnessed to determine whether spray should be used or not. I am not saying I'd spray those dogs.
As for inciting an attack by spraying them, I beg to differ. Those dogs know who the 'alpha' is and they follow its lead. When the alpha attacks, the others will gain the confidence to follow that lead. OTOH, if you can determine which is the 'alpha' and you take that one out, the others will likely be dissuaded from attacking. Dogs are pack animals as in followers. Bears are not. They do not follow anyone's lead and have built-in confidence.
Even lions have this figured out, kill the alpha hyena first.
I am a dog owner and lover just like you, but I wouldn't hesitate to spray an aggressive acting dog if it got too close.

