Thanks for the bump Viper, actually things just finished up ...
Folks pointed out that while the starter motors would roll the engines, they really wouldn't start. Recommendations were to focus on 'safety' interlocks, things that are overridden when the starter motor is cranking, but which 'safe' the engine (won't allow them to start) when they tries to run by themselves. Oil pressure, and temperature sensors were some of the recommendations.
Turns out a safety interlock was the culprit, my FireBoy system. During Irma it appears water got under my covered helm/dash and 'filled' the FireBoy's box connector box. As you can see in the picture, it was basically on 'slow simmer'.
Replaced the box at the helm and ran new wires to the unit in the engine room and everything's fine now.