I completely agree with the point you're making here. I would also agree that if the goal is to make the toughest folder the CS Spartan is fairly well engineered, but I also think it could almost be considered a failure as it is so overbuilt if the goal were to create an idea pocket knife.
I can't think of any other knife that is as strong though. Possibly some of the stouter framelocks that are out there. It would need be a design with a designated blade stop pin (aka not a standard backlock), Maybe an axis lock, or compression lock, but neither lock currently has a blade out thats as durable as the Spartan's. I tend to think an Emerson HD7 would give a Spartan a run for its money, as they are very stout knives in many of the same respects.
Maybe something like the benchmade bedlam but with a thicker blade 4mm maybe.