i had to sign up just to reply to this...
according to your logic, even an ork with a slugga and a choppa could obliterate a glitter boy, blowing holes and hacking it apart as if it were made of rice paper. so, basically, a good-sized warband could stumble out of a rift (they create holes in time as well as space, iirc) and totally dominate rifts earth in a matter of months, and even that would only be because they can't be everywhere at once. of course, their waaagh would create a mounting psionic link through the rift they came through, and draw more and more orks, so it mighten shorten the time needed considerably...
