| If people could destroy entire asteroids before they did any damage, how could troop transports possibly have a chance or landing troops? |
For starters, they ARE doing damage--they're killing soldiers. Second, the defenders might be busy shooting at the asteroids, too busy to shoot the transports. Third, and most obvious, perhaps an interstellar warship is more durable than an arbitrarily propelled piece of junk rock.
Also, I build my transports to look like they would be useful in an invasion. They have shielding on the front, the module is positioned where it looks like it could be separated from the hull for use as a landing spike*, and the ship has a number of extra bitz which look like they would be useful for invasion tactics (a broadcast dish for info warfare, some large heavy bomb-looking object in a launch position for bombardment, etc.). So
my transports would be expected to survive, though of course I don't know how yours look.
*You always, always, always lose transports used in the invasion (though it automatically holds your extra tranpsorts in reserve, so you don't need to break your fleets). So, logically, the transport itself must be used offensively, presumably to shield its cargo and serve as a big missile. So I build mine to look as though they do exactly that.
