The Cessna 170A & B had some washout in the wing construction, i.e. reduced incidence (and thus AOA) in the outboard wing. This makes the outboard wing stall last, improving aileron response through the stall. (Various sources quote the amount of washout between one and three degrees).
I expect the derivative 172 has similar washout. Does the PA-28 and its derivatives?
Washout has been a common practice in rigging prewar aircraft as well; it makes the airplane more "honest", albeit with a small potential performance penalty.
Of course, this raises the question "What AOA do you measure to define stall AOA? Root or tip?"