Thank you all who assisted me. This is what I decided to do in case my configuration is helpful to anyone:
Originally Posted by Dsanduril
b)use any one of the methods above (echo charger, ACR, DC-DC, ....) to combine the batteries when the charger is active. You might even be able to make the Promariner handle this function if it genuinely switches state when the ignition stud has voltage and it will work in "reverse", but the manual is silent on this subject so it would require testing. The simplest in this case would be as smac says:
I'm using the Xantrax Freedom XC to charge the House Bank directly (via a fuse). From the alternator, the Promariner connects to both banks directly, giving it priority to the Starter Bank. In between, I connected a Blue Sea Systems ACR 7610 that so far is charging
both banks via the Xantrex or the Promariner without overcharging any one bank.
I feel that I'm set. Time will tell if this configuration may damage any of the batteries, but according to my voltmeter, both banks oscillate between 13 and 13.4 volts, even when my wind
turbine is charging the house bank.
Thank you again and fair winds.