Since the random timing of hardware iterations and the eroding definition of what a 'new console' actually is, don't you think the handheld market has ceased to be head-to-head competition? Both companies have different strategies, and the systems' similarities are deteriorating, they're barely substitutes to each other anymore, feature wise.
It seems out of date to be assessing the release windows in that way, sure there is some sales cross-over but the times be a changing yo.