Salute Wiede
I agree with you about the decoding in the SMYD or two of them, if left vane to one and right to another. From there, looks like AoA value goes to the two ADIRU and FCC components. Since the pilot control had the shaker and from what others here have presented, I have to go with two of the SYMD's or a single one maintains the data from left for left ADIRU and right for the co-pilot side.
Unlike my trusty Viper, only one AoA can cause serious problems in the 737. Our system had the basic two conical AoA probes and then a serious looking hemispherical proble that used 5 holes to produce sideslip, AoA, static and dynamic pressures for use. We used a middle value prorocol from the two mechanical cones and one pneumatic sensor.
Maybe FC eng can find a better "flow chart" or "block diagram" like we old farts used back in FORTRAN IV and sliderule days, heh heh.
Gums sends....