If you draw a weapon, and have it pointed at the ground next to your leg- is that brandishing? IMO, probably not, as it would be hard to argue that the display is "rude, careless, angry, or threatening" but it will be for the court and a jury to decide.
How hard would it be to argue that the display is
not threatening? What was your motive in pulling the gun? You didn't take it out to clean it.
Brandishing? Maybe. Assault? Maybe. Think for a minute that they wouldn't press charges?
And of course it is not concealed--in many jurisdictions that's another violation.
If your action was not immediately necessary and something does then happen, you may have quashed your hope for even a jury instruction to consider a defense of justifiability.
In addition, should one of the perps attack you after you have drawn a gun,
they just might be the ones judged as having been justified in self defense. They don't even have to be carrying lawfully for that to happen.
Also, you may end up getting shot by a citizen or a police officer who interprets your action as one creating imminent danger.
If drawing
is immediately necessary, you wouldn't point the gun at the ground--doing so would likely weaken your claim of immediate necessity, IMHO.
It's impossible to second guess a situation without having been there, but I don't think drawing on someone 75 yards away would be very easy to justify at all. The question has been properly asked, how close do they have to be before you do have to act? There are four of them--that's ability; if they close the distance sufficiently, that's opportunity; the remaining question is one of immediate jeopardy.
So far, there is no indication of violent intent. Probably the best way to determine whether jeopardy exists would be to change course yourself--cross the street, for example--and see what they do then. That should answer the question. If they go on their way, that's one thing. If they follow you (and are clearly doing so), you have tried to avoid and evade; the next question is whether escape is safely possible; and the next, I suppose, is whether retreat is
required.
Yeah, I know, people like to crow about "stand your ground" laws and such, but I'd rather try to defuse the situation, and failing that, have a much stronger and more supportable defense should bad go to worse and then to worst. You can change direction as a defensive tactic without "retreating" and you don't need to argue about perfect safety or anything else to use that option.
By the way, the OP is not covered by a stand your ground law in Pennsylvania.
Personally, I'd like to live in a state in which casually moving my shirt aside without touching my holstered weapon would be permitted.