Something else to bear in mind, and it is something that you won't find out until you get the chance to try it
That some dogs react differently ON lead than they do OFF lead.
It's part of the Fight or Flight reflex.
ON lead they can't run away from a potential confrontation, because they are tethered to YOU, and so act aggressively to approaching dogs.
OFF lead they can run away and so the same approaching dog is allowed to get closer and have a sniff.
My Echo is a perfect example of this. OnLead she will act very aggressively towards people or dogs who approach us.
Off lead she will mingle quite happily with dogs and people, the same dogs and people she was on her back legs barking and snapping at just moments before.
If you have the chance to let Smokey off at the meet (assuming there is a safe enclosed offlead area)
Then you can find out if He is onlead aggressive or simply just doesn't like all dogs regardless.