One of the nice things about 12 volt DC systems (All DC systems) is that you can parallel 2,3,4,12,100 different power sources and they won't compete.. Now it may happen that one will provide all the power, and the others sit there and relax.. (This is how that "Automatic battery switching" happens by the way.. The highest voltage source provides the power).
But I'm not clear on what you are planing. a 100 watt (10 amps peak) solar panel via a 30 amp Controller to charge the batteries and a 1,000 watt inverter. Why the 3 amp battery maintainer?
Or is it the 100 watt panel charges HOUSE batteries which power the Inverter which powers the maintainer which charges the CHASSIS batteries. .that should work.. provided you have enough solar power.. I'm not sure you do .