I've designed PCBs using connectors with multiple parallel wires to carry high currents. It's hard to do, and very easy to mess up during later PCB changes. You have to match trace resistances from each pin to the destination. The resistance in the traces is probably higher than the resistance in the wires, so the wires don't help balance the current much.

It's easy to mess up during minor PCB changes because the netlist doesn't capture the important bit. An autorouter would happily connect the pins of the connector together and cause uneven current sharing.