Pre-Retcon Beyonder has been fiddling with a parallel universe and sent the movie versions of Aragorn, Gimli & Legolas to Minas Tirith before they can get the assistance of the Army of the Dead.
They, along with Gandalf, have to watch all the Marvel character based films (Avengers, X-Men, Spider-man, any I've missed) and can select 10 heroes to assist in defending the city. Time is frozen in Middle-earth for everyone else so they can watch them several times if needed.
Theoden brings his men at the same point as in the movie and the pirate ships supply reinforcements for the force of Mordor.
Who would you select if you were them?
How more or less easy is it to defend the city?