I suppose when people say that they take into account something like this: 4 Examples
Curry offense 100%, Curry Defence 70%= 170%
LeBron offense 90%, LeBron Defence 80%= 170%
Durant offense 100%, Durant Defence 70%= 170%
Leonard offense 80% Leonard Defence 100%= 180%
Hence, Kawhi is the best 2 way player in the game. But take into account Curry and Durant's offense is more like a 120% in the scheme of things giving them 190%. But as there's no such thing as 120% they 'only' get 100% so Kawhi gets the nod for best 2 way payer. Maybe that's a formulation they take into account when saying that. But yes it's a bull thing to say anyway.