I think you are over estimating how much power you need for propulsion. Not a bad thing, but I suggest some thinking on this.
Using OceanVolts calculator
https://oceanvolt.com/configurator/#power
They only recommend a 6 or 8kW motor, and cruising at 5knots requires 2kW.
Those old diesel motors never put out the nameplate horsepower unless you were running them at redline.
Also, as someone in a similar situation. We are doing an Oceanis 400, replacing the Perkins 50 with an ME1616.
I am design a custom boost charger for each panel to maximize MPPT.
Based on the LT8490 IC it will be well suited for 200-500W panels boosting 16S LFP system.
Ill have more information on this in a few months if you are interested.