<chuckle>
OMG! We have figured out how to use "the other guy's" spear! We must tell everybody because...you know...our guys never win a fire fight and never capture the opposition weapons. And, even if they did, plain old infantry is too stupid to figure the simplistic operation of the opposition rifle.
Jeezus! We'd better make ourselves look important and useful by telling everybody how to operate the other side's rifle!
The military has manuals for everything, including how to disable equipment so that the enemy cannot make use of it. Not all enlisted recruits posses the same level of electro-mechanical-firearms figure-it-out-on-our-own kind of abilities or motivation as maybe some other folks have. A manual provides much more consistent training than would word-of-mouth from instructors. Training of the military, and setting standards for the training of the militia are explicit duties of the federal government under the constitution.
Furthermore, the middle of a firefight might not be the best time for some poor, ignorant, or stupid private whose only training on firearms was his official military provided training on his rifle to figure out how to use the enemy's rifle he just captured and desperately needs to use because his is out of ammo or broken.
The only one trying to make himself look important without cause here is the one who consistently tries to attack anything associated with government.
Charles