My point is that as pitbulls have been illegal in this country for 20 years, it's unlikely that the dogs you saw were actual pitbulls.
There are many of them. Either pit bulls, pit bull types, or dogs with some pit bull in their heritage, and they are everywhere
Many dogs look similar, especially if crossed with other large breeds
And there is the problem in a nutshell
For a dog like a Staffordhire Bull Terrier for example, AKA a "staffie", this is why measurements, head, jaw, neck are the best way
I would include staffies with large heads, jaws, neck etc, over a certain measurement, to be phased out.