Other mistake: During the scene when Pilla is killed there is a sniper on the roof of a building firing an AK-47 at the vehicles. If you look at his hands you'll notice they are caucasian. The other Somalis are black. (00:46:25)
Other mistake: In one scene a pair of soldiers cut off from the main body of troops are trying to link up with some of their comrades. When the camera zooms in for a close-up of the soldier carrying an M-60 machine gun, the weapon appears to be loaded with a belt of blank rounds. (00:54:35)
Other mistake: The credits (and various websites) lists Canadian-born actor Kim Coates as portraying the character Wex, but he actually plays Master Sergeant Tim "Griz" Martin. (02:12:40)
Other mistake: When several of the Rangers are carrying Blackburn's litter up to the target building and they cross an intersection, you can spot an empty, stationary Black Hawk helicopter at roof level further down that alley/street as one of the Rangers fires at the Somalis. This was after all the Black Hawks had gone into their holding pattern. (00:48:15)
Other mistake: During Mike Durant's capture the helicopter circling overhead that broadcasts "Mike Durant we won't leave you behind!" is the voice of Tom Sizemore who plays Col. McKnight - it even says so in close captioning." Col. McKnight was in the streets of Mogadishu engaged in battle at that time. (01:44:45)
Answer: The answer to this question is quite simple. Whenever any book is put on to the screen things must be glorified in order to catch the eye of a film goer. In movies like this one, heroes, brave men, and down right bad ass characters are what people need to see. If the movie was just like the book, there would be just a whole bunch of equally important characters, which is something very rarely seen in movies. So in short they made sgt Eversmann a main character simply because the movie needed one.
That makes sense but does anyone know why Eversmann was the specific soldier chosen as the focus for the movie?