[PvK]

Good question csebal.

This was partly done for counterpoint. In the unmodded game, an artificially low limit on planet capacity ("Sorry - _planet_ "full"!") results in planetary defenses being incapable of fighting off a fairly large fleet. So it both makes sense and offers a new situation.

In theory yes it is possible to put an enormous amount of units on a planet with a breathable planet - particularly the homeworld.

In practice, there may be a very large number of units on important planets, and it makes sense to take advantage of this to protect them. However, there is not a stalemate situation except potentially with a human defending against the AI (due to its weaknesses).

One simple reason it's not a stalemate is that you don't have to fight the weapon platforms if you have your ships not fire on planets. The planet is then blockaded, and this can effectively remove even a homeworld from effective contribution to an empire.

Also, in practice, it's very expensive and time-consuming to build fleet-stopping defenses. In the time it takes to build them up, they become less and less up-to-date, too. It's usually a better strategy to concentrate on mobile forces and economic development, with just enough defences to prevent your planets from being snatched by cheap raiding forces.

Finally, there are weapons which can overcome even a formidably defended homeworld. Planetary weapons do huge amounts of damage, and there are shield-skipping and shield-depleting weapons which can still overwhelm a powerful planet... but it's generally risky and expensive, which is how I intended.

One vital tip is to scout first - send ships to view the defenses before assaulting. Also, custom anti-planet designs can help - expendable with cheap components (no expensive sensors, top-end engines, or elite crews) but lots of cheap armor and effective anti-planet weapons are good choices.

PvK