Warning: Major spoilers below.
In the operation to retake the Founding Titan, the Female Titan, the Jaw Titan, the Armored Titan and the Colossus Titan were sent for it.
In the last episodes of the Season 3 of the anime, we see the Armored Titan, the Colossus Titan, the Beast Titan and the Cart Titan fighting Erwin, Eren, Levi, Mikasa, etc.
Why was the
War Hammer Titan
not involved in any military operation until at least the 3rd Season of the anime, if he also is in the power of the people of Marley?