Ours came stock with everything off one post also/ 2- 12's.
Switched to 6V batteries and everything is off one post again. I guess your manufacture figured the three slides needed their own power source for some reason? Just me but I want all the power I can get when bringing those slides in, especially the BIG one.
2015 Tiffin Phaeton Cummins ISL, Allison 3000, 45K GCWR
10KW Onan, Magnum Pure Sine Wave Inverter
2015 GMC Canyon Toad
Previous camping rig
06 Ram 3500 CC LB Laramie 4x4 Dually 5.9 Cummins Smarty Jr 48RE Jacobs brake
06 Grand Junction 15500 GVWR 3200 pin