The RA was mentioned in the FCOM but it was very easy to miss. The same single source issue is also relevant to the 737 autobrake system in that it uses the L IRS for deceleration rates. Again the cut to training foot prints across type ratings ensures less systems understanding compared with the way type ratings used to be taught.
It is time safety was placed at the top of the Corporate tree instead of huge operating profits. Training is expensive but accidents aren't cheap either and then there is the loss of life ,which can never be replaced with money from law suits.