25 Spartans (Halo) vs The Chitauri Invasion (MCU)

Spartan IIs with their latest armor and a UNSC handgun and battle rifle.

5 up high on rooftops have Spartans Lasers, 5 have Rocket Launchers, and 5 have DMRs as well.

5 in the sky have AV-49 Wasps, and 5 on the ground have Armored Gauss Warthogs.

Ammo isn't an issue, and routing the Chitauri is a win. They probably can't close the portal but their AI might be able to.