How to increase current capacity of an ideal diode circuit?
You would probably be better to use large module-type MOSFETs or parallel smaller MOSFETs as shown in the datasheet. 

MOSFETs have a high temperature coefficient of Rds(on) so to get them to share better, it's good to have them relatively thermally isolated from each other (ie. individual heat sinks) so the one hogging the current gets hotter, and thus hogs less current. 

Using two chips with separate MOSFETs could cause problems as the chip uses a closed-loop controller to maintain constant voltage across the conducting MOSFET and two of them could interact and cause instability.