Stall is very relevant to speed seeing as it's the only indicator a pilot has (apart from any aural or buffeting effect) That's why they have a white arc on the speedo, the lower end of which represents the stall speed in a certain flap config for Eg.
AoA is the dynamics of the actual stall (as has been mentioned)with regards to wing shape & any delaying devices used, the leading up to it is only shown to the pilot by the speedo:-)
It is my opinion that the speedo is the single most important inst in a plane, that plus the other important commodity, height of course
Good to see healthy discussion here about a killer disease & good ref by 'JT':-0)
Wmk2