When I compared the WC to the RB6 wishbones the length hinge pin to hinge pin seemed the same, it was the shock positions that are different and the end where the hubs are there is more of a cut away on the WC wishbone.
The difference is in the bulkhead part, the bit the inner hinge pin slides through
The way I see it you have now 3 different widths... Widest RB5, then the RB6 then the RB5WC
Plenty of tuning options!