Plus the original concept had the dish at the equator; they even got so far as to create the final matte painting for it before it was decided to move it up to the top half to give the thing a (iirc?) clearer sense of orientation and a more interesting look.
Indeed, that's why the computer model of it in the briefing retains that design: redoing it was simply out of the question since it'd require reshoots with the cast and extras.
So yeah, Mimas turning out to look how it did was purely coincidental.