They both face major deficiencies trying to go the other direction.
However, many will say it's easier to scale up than scale down. After all, you can always use "big war" equipment to blow shit up, but light infantry never fares well against tanks.
At the same time, trying to honor every threat equally causes as many problems as it solves. You have to base your planning and purchases around the most likely contingencies, not every contingency.
You can take four snow tires with you when you're travelling to Mexico, just in case there's a blizzard, but it'll probably just detract from your original mission of watching the donkey show in TJ. You go down the street trying to find the place somebody told you about. Meanwhile, your buddy thought he would get a BJ in the back seat from a stripper, and he's too drunk to get the tires outta the back seat, so he slips, falls, passes out and gets beaten and robbed by the kids you didn't buy Chiclets from. You finally get back to the car, and it's gone. You don't have the money to bribe the Federales to get the car back, because you blew your paycheck buying the damn snow tires. So you're broke, stuck in a shithole, your buddy's in a Mexican hospital with a doctor who got his degree in Panama, and Juan the patrolman is driving your brand-new ride, all because you decided to cover any conceivable possibility.