This lets the game reward skilled players, since with proper timing, you can effectively charge through and destroy hordes of lesser enemies quickly. (hardcoregaming101.net)
Even on the normal difficulty setting against a group of lesser enemies combat can be a harsh master if you're not fully prepared. (thatvideogameblog.com)
You'll inevitably drain your ammo in the process, so the game also continually spawns lesser enemies during the battle primarily to serve as ammo loot droppers. (gamerstemple.com)