Nope
Not even gonna get sucked into this one. I wouldn't bother to show up.
By the time I got there you guys would have already cleaned up. This is just not fair. 16k guys armed with 100's of rounds each, against what was the number? 20k Orcs? Heck if we had 1600 guys show up, each with 100 rounds, shooting at something not shooting back. I'd give you a hit rate of 80% at 300 yards. That means you've got the potential to kill 100,000 give or take. What with that many I'm sure many of you would be taking single goblins with multiple bullets. And with such a huge horde you could very likely shoot into a 30 radius on the horizon and not miss.
Naa, I would predict you guys would shoot the first wave and they would be repealed. But, this would probably mean they would then come under cover of darkness. How many have light amp. or thermal scopes for their rifles?
Also I'm thinking about the flying lizard things. The combination of Big Flying Lizard and wraith are probably your most dangerous opponent. I guess I am wondering, can a bullet kill a wraith? After all they are undead right? Sorry, I HATE Tolkein's work with a passion. So a LOTR geek is going to have to chime in on whether or not a wraith can be killed. If he bleeds you can kill it. But if you can't...I don't like your chances. Heck a sword doesn't run out of bullets. Now if shooting him does not effect him you have to plan on trapping or caging such an opponent...hmm.
This needs some more thought than just guns and bullets. Give up on the planes and the nukes. The logistics of this scenario don't allow for this. It sounds like YOU and what you can carry get transported there. Not you and your favorite vehicle.
Okay, so smart guys. Answer this now. What do you do about the wraiths? And what do you do if they regroup and now attack at night. Or use hit and run tactics?