Orcs Assault Your Planet

A vast industrial world, it has large cities with robotic factories dedicated to producing ammunition. This is both a blessing and a curse. On the one hand, you won't lack ammunition to fight the orcs. On the other hand, everything is full of explosives.

About 100,000 men, but they are armed only with laser rifles and no notable heavy weapons. They are also poorly trained or disciplined, but they fight to defend their home. An Imperial Guard regiment can arrive within a week.
The commander of the local garrison is Scaloni, a competent man who knows his resources are limited. The governor of the planet is Menem, and he is extremely corrupt.

The Imperial Guard has a regiment nearby. They are fewer in number than the local garrison, but they are better equipped and trained; they have artillery, tanks, and heavy weapons. They are commanded by Colonel Facundo, an ambitious man willing to prove himself. They are supervised by Commissioner Emiliano. This commissioner is different from many in the empire; he is wise and will order the evacuation of the planet if he feels he cannot contain the orcs.

The orcs, or greenskins, arrive with a large army, some 90,000 boys ready to ride "waaaagh," plus thousands of their gretchling servants. They are tremendously aggressive, loving close combat and explosive weapons. All they want is a good fight to honor their gods, Gork and Mork.
The orcs have enormous machines, but they seem to be made of scrap metal. They are led by their warchief, Mape elden gruk, a 6-meter-tall and very aggressive orc chieftain.