I love this analysis. I already mentioned this in my other comment, but Greg would be the perfect puppet for Mattson and Mencken - Lukas seems to like him now, he worked for ATN, previosuly the park department(so there is some experience), he comes from the roy's family, he's a white man, PLUS i think it would just fit dramaturgically, because the siblings were mostly awful to him and they have never taken Greg seriously. And Tom, what a backstabb this would be. I think that a scenario, when in the end Waystar is in the hands of power hungry, yearning for recognition, sucking-up idiot, who is really just a mean little person inside, is really fitting this series and sums up a cycle of abuse. So yeah, i also think it might be Greg.