There are several things happening that you do not show with your meter readings. What you do not show is the increase in amperage, and voltage drop, when one of your AC units is first starting the compressor. This can add several more amps as well as drop the voltage 2-5 volts for a short period of time until the compressor is up and running.
Another things is that as the voltage drops, your amps used will increase for all electrical items in your coach.
If you hear your AC compressors struggling to come on, that is the best indication that the voltage is too low. This is especially true if the AC compressor cannot get started and drops back in to a fan only mode.
Volt meters are fine but they only give you an instantaneous voltage reading on a power supply that is constantly changing.