I agree with TB in one regard, the whole "land battles" aspect of the game seems to be handled very badly. I as well have found no way to determine which races actually excel at "ground invasions", or even how to tell if ground invasions are happening in the first place, who is winning, or what is going on whatsoever. Basically, from the player's perspective, a native planet is being surrounded by a swarm of foreign ships, then eventually it's conquered. There's really no indication or explanation of when or how the ground battling begins.
Before I played the game (reading about it before it even went into Alpha), with all the nuances and effort the developers put into the unique attributes for each race, especially in terms of their space and land invasion differences, I simply assumed that ground combat would have its own "simulation" itself, or at least a very visible indicator of how the battle was going. What we got instead were a few obscure numbers, difficult to find, it's such a huge part of the game and yet seems to be so difficult for the player to be involved in it.
Like I said, it could just be that both myself and TB never figured out how to "view" this part of the game, and if so I'd love to know how to do that.