The "V" and "i" mark that Oli draws on the Jeep during the maneuvers, changes style and size between shots.
There's no way Hardy could have been drafted into the army with his weight as high as it was.
These new inductees have way too much free time. As a trainee, the Army runs you ragged until you finish with basic training. The only time you have off is just before you hit the rack. Especially in the first four weeks. In some cases, you get some time to go to the PX. But it's rare.
The 10th Cavalry was the segregated Buffalo Soldiers so while there may be some senior white officers all the NCOs and soldiers would be Black.
Laurel and Hardy were too old to join the army.
The "dud" they find is a complete round. It could have been a misfire/hang-fire but not a dud. A dud would have only included the shell. Not the brass too.
Right after Oliver says, "Those blue boys couldn't hit the side of a barn". He sits back and closes his eyes, and hunkers down, as he waits for the flour bag to hit him.
The gun powder in the Hippo's pipe was enough to blacken his face. But, it didn't touch his hat.