it's obvious that he's not the only boss
Right, there were other bosses as well, but Lasker is the boss of all bosses. Be it Rubinstein, Pillsbury, Capa, the 1...Nf6 guy, Nimzo, Tarrasch, Schlechter...
Which means that it's possible to be a boss without being Lasker, thus the boss =/= Lasker
it's obvious that he's not the only boss
Right, there were other bosses as well, but Lasker is the boss of all bosses. Be it Rubinstein, Pillsbury, Capa, the 1...Nf6 guy, Nimzo, Tarrasch, Schlechter...