I'm certain that if one were to write 40k via code, that the computer would with out a doubt be able to beat a player, and over time with enough testing/patches to beat some of the high end "professional" players of 40k.
you are on the right track, here.
trying to beat an AI computer game,
or go or chess for that matter which are basically human beings trying to make computer games before they had computers, so that the games are themselves - we can say - originally intended to be coded, in the end,
is like challenging a fish to a swimming race.
but this goes both ways.
that is the essence of the original post, really.
and "competitive" 40k is for wanna be necrons.