The Fellowship Vs Skynet
Due to a C++ critical error Skynet is led to believe that Frodo must be stopped and sends a T-800 (Arnold T1 & T2) through a time-space-dimensional rift to Middle Earth during the time of the LoTR with the mission to kill Frodo.
The T-800 arrives naked and quickly kills an Urak-Hai while he's taking a piss and takes his clothing, armour and weapons(shield, sword and spear) and intercepts the Fellowship as they're approaching the entrance to Moria; they believe this human dressed as an Uruk to be some minion of Sauron.
*T-800 - Uruk sword, spear and shield (has been programmed with the knowledge of how to use said weapons)
Vs
*Legolas - Bow, Twin Long Knives
*Gimli - Battle Axe, throwing axe
*Aragorn - Sword, dagger
*Boromir - Sword, dagger, shield
*Gandalf the Grey - Staff, sword
The Hobbits are there and can factor in, though Frodo must survive.