However, this seems to me like EXACTLY the kind of case where display of a firearm may be the best bet. He's still too far to effectively close prior to potentially being shot, but near enough to see the gun and decide that maybe he should abort his current actions.
I don't think anyone was arguing that there weren't situations where it should be done, I know I wasn't. In my post, it wasn't recommended because legally, it hasn't been tested in court, and no one really knows the outcome. The difference in situation between where you can defensively display and where you can use deadly force is very close. In most cases, it isn't wise to show your "ace in the hole" until the last possible moment.
Most states (that have defensive display laws) require imminent threat of physical harm or greater to legally display. In the case where someone is too far away to cause you harm before you could draw, it would be illegal to display, and you could get arrested (at least in AZ, won't speak for other states) for aggravated assault. In your first case, in AZ, if he was not an imminent threat (and someone with a baseball bat at 20 yards is likely not imminent) it would be illegal to display your gun. Strong words, and a defensive posturing would be all you could legally do at this point. If he continued and got to the point where he was an imminent threat (baseball bat is considered lethal force), draw down and see what happens. At this point, you are covered under use of lethal force, not defensive display. Granted, a test case could potentially find that this situation is imminent, but this is why it was recommended to me not to do it...because being a test case sucks.
In the second case, dogs that are trained to attack, are usually considered lethal force. If the dogs are close enough to be considered imminent, draw down...you are covered under use of lethal force laws at this point...not defensive display. If they're not far enough away to be considered an imminent threat, you are not likely covered under defensive display. Keep in mind that in this gang bangers with dogs situation, bringing out your gun if you don't have to use it might cause them to sic the dogs on you, and draw their own guns. Now not only do you have two dogs to deal with, but two guys with guns. It might just escalate as a result...but here I am What iffing your situation. I see someone who is dressed like a gang banger, I assume they're packing.
Of course, this is all talking about AZ as I don't know other states individual laws. But this is why it was recommended not to use defensive display, because the situations where you can likely legally do it are incredibly narrow. There are very few situations where you would be covered under defensive display, but not use of lethal force. And even in those few, narrow situations where you could use it, it might not be wise to do, tactically, until it does escalate to an imminent threat.