There's nothing wrong with just replacing the terminal if the cable is good. Mcgyver wouldn't fix what isn't broken. That being said, if the cable is corroded (and yes they corrode on the inside of the insulation too) you might as well replace it. When I replace ground and positive cables I usually upgrade to the heaviest gauge cable that will fit the connections it needs to make.
Personally I don't like Ford's terminal design on this cable. They wouldn't tighten all the way onto my replacement battery terminals even though the battery is the correct listing for the car. I had to get creative and make a shim, similar to what the last poster was saying. You don't need to use the same terminal type that Ford did, anything that has a place to put the extra smaller wires that come off of it will work fine.