Thanos has a very apparent upper hand
In order to even consider taking on an Infinity-Gauntlet-Wielding-Thanos and his Black Order, all of our heroes will need to combine their efforts — which doesn’t seem likely since they all seem to be fighting a separate battle.
The Cap, Black Widow, The Winter Soldier, Black Panther, War Machine and The Hulk seem to be dealing with conflict Wakanda. Thor and The Guardians will likely be dealing with tracking down the Asgardian Vessel seen at the end of Thor: Ragnarok, facing the destruction of Xandar, and retrieving Jarnbjorn. Spider-Man, Dr. Strange and Iron Man clearly have their hands full in New York with the circular spaceship seen throughout the trailers.
Only time will tell how the first installment of Avengers: Infinity War will play out, but the stage is most certainly set for an epic film.