Of course, its crew was vulnerable to everything out there. A bazooka could blow up any vehicle. However, it did not blow up a bunch of troops. A flamethrower could burn out a tank. A missile was like a big cannon.
Hand grenades are like a mortar, but they are thrown at close range.
Airplane bombs could blast anything except tanks. Civil War, Revolutionary War and Pirate cannons could not harm tanks, half tracks, armored cars or self-propelled guns. Civil War mortars acted like regular mortars. Nukes destroy both sides, so nobody can use them. Civil War Cowboys, Pirates, Davy Crockett guys and Alamo Texans could be used to supplement either side.