Ya....with all their gear(if you include the Stars from the Mario games gear) then Link and the Mario bros will be the only ones left standing. All their gear, makes them pretty much immune to any damage...of course Link however has the advantage here.
Magic Armor + Deity Mask + Four Swords + Pegasus boots + Golden Gauntlets= 4 godly master swordsmen, super fast, super strength, indestructible Links.
The Mario Bros Stars will only last a couple of seconds, once that is gone then Link just destroys them. He has way more versatilty with his gear, as I mentioned in one of my threads he and Batman are pretty much the same guy, and both of them being the most dangerous person in their trinities given all their gear and such.
Well, as was pointed out, several characters have access to invincibility. Also, Kratos can time travel without equipment. So unless you want to ban time travel entirely, Kratos can win via time travel.
If we were going to ignore BS mechanics completely, such as time travel and invincibility, the Kratos and Link team stomps. They have too much utility and offensive powers. Aside from all the stuff listed for Link, Kratos brings a lot to the table too with his immense physical strength, soul ripping powers, petrification, ultimate defense via the golden fleece, etc.
By game mechanics, Kratos can also become invincible btw. The power of Hope in God of War 3 makes Kratos invincible. The game even takes away your health bar.