There's so much busted in the SST film it's hard to know where to start. The tactics and gear are wrong -- in the book, troopers wear powered armor and certainly do not use stupid WW1/WW2 era tactics.
I was always disappointed that we never got to see the Marauder suits on screen. In the movie, the fights are massed close combat, with the mobile infantry almost shoulder to shoulder, wearing what looks like cheap plastic armor that doesn't seem to do anything, and running around like ordinary people with exposed faces. It's tight, close, personal, and human scale. They frequently faces hordes of enemies, but they're treated as cheap and disposable.
In the fbookilm, they wear massive suits that makes them look like giant metal gorillas, with jets they can use to bounce across the battlefield, while spraying massive amounts of firepower, including strings of baby nukes. They're widely distributed, the distances covered are vast, they have enough firepower to take out cities, and they have sensor arrays that make modern fighters look blind.