Bill Wallace countered that 99% of all fights start standing up. I think preparing and training for both and anticipating neither is sensible. Either the opponent will be better or not. If he's a better grappler, then striking will be at least as useful. If one's a good grappler, it makes sense to use that advantage. If the opponent is a better grappler and striker, what difference will it make whether the fight is stand up or on the ground?
I think the stats in the article are probably correct, though.