The game's tutorial is fucking garbage. It functionally ends at the basic RTS controls, then leaves you on your own to sort out the complex unit interactions. It's not a game where you can brute force situations in, particularly if you've got buildings to take down. I came into it with knowledge from binging youtube and it's still opaque how this is supposed to be played.

The campaign AI tends to aggressively stripmine and rebuild, leading to them being impossible to take down except in a single overwhelming strike. Basically, if you're slow or unsure (as new players tend to be) it's very easy to run into stalemates where you don't take significant losses but also can't find a way to make progress against them. I've had multiple cases where a mission turned into a 3-4 hour shitshow and frankly fuck anything that devolves into such a waste of time.