If you want to do 6s2p but are concerned it could be backwards, therefore excessive Isc could cause damage,
start by connecting just one string of 6s. If it powers up and sees voltage, then shut down, connect second 6s in parallel, parallel back up.
If you orient one 6s South East and the other South West, instead of 2x the current it will only be about 1.5x
Controller says 18A max Isc? Or max operating current? Full spec sheet would help.
If 2x current of panel exceeds max operating current, then using two orientations helps avoid clipping and losing power.
But most of the time sun will be off angle, also panels will be hotter, and current is reduced.
If wires are polarized and correct then it won't get connected backwards. If polarized and incorrect then it will.
Does inverter come with MC4 connectors pre-attached? Most of us have screw terminals so we're the ones to connect them wrong.
Good to check voltage and polarity with a meter before turning on PV disconnect.
