Yeah... to say it needs work is putting it nicely.
It has that all-too-common sense that everything happens for no other reason than it HAS TO to get the characters where they have to be for whatever the author wants to do to them. It doesn't feel natural. There's no proper tone or context, and without that I can't buy into the world.
Are they wearing Stahlhelms and wielding Panzerschrecks? It seems as if the 1940's Wehrmach found themselves a portal to Equestria. Those crazy Nazi scientists. Maybe this is why they lost... they secretly attacked yet another nation in the midst of WWII.
What creature is this extraordinary guy behind the leader? And why do these soldiers' uniforms and equipment look like they were from WWII (on earth)? (too lazy to and not really interested in reading the fanfiction)
Here's hoping they brought enough anti-magic equipment to deal with all the excessively powerful magic being used there, I'd hate to see them all defeated by Celestia raining down havoc on them with a simple thought. Here's hoping for more non-magic users being seen as strong threats in Season 4! :3