Making a bazooka much more like a gun on a sailing ship, able to time their fire with the roll of the ship, while a howitzer would be more akin to a mortar on an 19th century bomb ketch, where precision of aiming, powder needed for the shot and timing of the fuse are arrived at by trial and error. (I am reading through the Hornblower books for the umpteenth time, so Napoleonic sea warfare is fresh in my mind.)