Redditor Kronos9898 erklärt im grandiosen WhoWouldWin-Subreddit (für jeden Freund nerdiger Debatten sehr zu empfehlen) in einem genialen Post, wieso die römischen Legionen Mordors Ork-Armee locker aus Mittelerde vertreiben würden. Da hätte es Frodo einfacher haben können… Take that, Tolkien!
I believe people are seriously underestimating the Roman legions. First, let us talk about the size of the Roman Army under Trajan. The largest number I can find for the orcs is 250k at Pellanor Fields. This represented the vast bulk of Sauron’s strength, if memory serves. The Roman Legions under Trajan are estimated to be around 350-400k. Keep in mind that a large majority of these troops are battle-hardened career soldiers.
While there may be initial shock value in the first engagement, the hallmarks of the Romans were adapting their tactics to suit their enemies. The Romans developed sophisticated methods to deal with war elephants, for example. It is unreasonable to assume they would not do the same for Mumakil etc. Keep in mind that Mumakil where effectively routed by a force of 6,000 Rohirrim cavalry. To say that the Romans are not capable of the same with their already established superior number is ludicrous.