One of the first things that comes to my mind is the “type” of catapult. For example, is it a modern catapult like this one: Or is it a catapult like this one: If you do the maths, 1 catapult needs to kill 30 spartans. read more
This is a simple case of a technological edge on the Templar’s side. Spartan’s primary weapons are made of bronze and iron while the Templars use steel. The Templar’s were also covered head to toe in armor. A Spartan weapon probably couldn't even pierce a Templar’s steel armor. This is ignoring cavalry on the Templar’s side. read more
At their height, the Spartans could field an army of 6,000, about the same as a Roman legion including auxiliaries. Rome from its beginning could levy 10,000 citizen soldiers. Sparta would win any field battle against the Romans at this point. read more
Since Spartan ships are larger, heavier and made for ramming and skirmishing forces to board enemy ships, the Spartans win this round. Vikings can shoot at the Spartans since Spartans don't believe in long range warfare, but that won't work out too well in the end. Round 2: Vikings were excellent fighters, much like Spartans. read more