There are many different categories in a comp to target. As it was, several different categories were won by differing boats which is not always the case.
Carnage had '3' sharks, two of them (Blue) on 6kg & one (Mako) on 15kg for three different anglers.
Black Pete's fish were great fish and they would have taken out capture if they were both captured on 37kg (one was on 60kg line class). Any one fishing capture knows roughly how the points systems works - heavy line class is penalised as the fish weight is divided by line class (as well as factoring for various sharks vs tuna vs Marlin).
Black Pete didn't take out champion angler either for the same reasons above - but could have if both were caught by the same angler on 37kg - before the recent changes to NSW fishing rules that only allows one of each species of marlin per angler per day, captured.
They obviously won heaviest marlin, which is probably exactly what they were targeting.
So not quite as simple as it may appear....