Being a text-based game does indeed give us options. I personally feel that planet-based units would be a tremendous bonus to the game. The downside is that it would probably be a complex addition.
Personally I like this idea, but there is an potential problem. Should a new 'resource' be added, one to measure the population on the planet? How would this work? Would it affect fleets and defenses? Mines? Many people would be less than thrilled at this concept, and it would be a major change.

As complex as it seems (and I'm sure is) to add a 'landing craft', it seems to me the better option. If infantry are treated as cargo, why can't you transport smaller ships like light fighters? So I think that while this is a great idea, it will take a tremendous amount of thought and effort to implement it as anything more than another defensive unit. Transporting them in the cargo seems simple, and I can understand why you would do that, but it seems to me something a bit more complex would be more beneficial in the long run. I will think something up eventually and post it.

The idea as it has been presented is actually pretty good, as the unit is fairly weak, effective in defense against other ground units and in offense against ground units and defense. It however needs a lot more planing before it is ready to be implemented as it is meant to be-to implement it as a defensive only unit would defeat its purpose.

you dont really need to make it that complex, you dont need landing craft and all this other hoopla. i dont want things complex. the more complex it is the more likely it would be rejected and the longer it will take for it to be implemented. its fine the way it works. scripting is not easy you know.