Making sure I need a D300S for my solar panels

I have 6 Solaria PowerXL-400R-PM solar panels being installed since I have two MC4 inputs and two batteries for my AC300 do I even need a D300s? Seems like connecting 3 panels to two MC 4 connectors 1200 watt 153.3 volt PV input and 3 panels to the other two MC 4 connectors to the 1200 watt 153.3 volt PV input should work without the D300S - does that sound right? Or am I missing something?

Yout setup is correct. You don’t need the D300S.

Unless I am misunderstanding your connections, if you hook up 3 panels at 51.1 V each in series, then you are over the 150 V max, in fact you should keep it below 143V because of increase of voltage with a decrease in Temperature. So even using the 48.1V x 3 = 144.3 in cold may/will be a problem.