In my boat with 2 engines, a Victron Skylla IP65 charger, 2 Argofet 100-3, Cerbo GX, BMV 712 smart shunt are installed. The batteries are AGM 95 ah for starting, AGM 95 ah for thruster, and a new Lithium bank with 8 cells of 314 AH, 123 Smart BMS, which provides 12V and 628 Ah.
To protect and not burn the alternators, I have been told that Argofet does the job of controlling the current and regulating the charging current.
Other arguments are that Argofet does not regulate the current, but controls which battery to charge. And that a DC-DC charger like Orion tr smart should then be installed, which regulates the charging current.
The Argodiode 100-3AC is a battery isolator. It takes a single alternator input and splits it up for up to three seperate battery banks. They can compensate the alternator output voltage for their own internal voltage loss. What that means is, due to passing through the internal diodes, there is always a certain voltage loss across an Argodiode module. The module comes with a compensation output which is meant to be connected to the alternators battery sense line. This will then in turn raise the alternator output accordingly, so after all you get essentially no voltage drop out of the Argodiode. Thats the whole voltage control part, it is definitely not meant to control charging voltages for an LFP battery.
An Argofet 100-3 works in a similar way, but due to using FETs internally it haa almost no voltage drop, so a compensation is not necessary.
To charge your LFP house battery, you can use one of the outputs to feed an Orion. Since the Orion Smart are buck/boost battery chargers, they can regulate and control their output voltage.
With an Orion XS or Orion 1400 you also get current control. So you can set a limit for the input current according to the alternators you use, and for the output set charge voltages according to the LFP battery as well as a seperate current limit.
Orion Smart/XS/1400 also can be controlled by DVCC.
Orion Smart/XS/1400 are battery-to-battery chargers, and usually its not advised to connect them directly to an alternator. However in this case this is ok, since the starter battery of the respective engine is also connected to the alternator through another output of the Argofet.