>AOTC
Bugs design superweapon
>ROTS
Deathstar is under development
>R1
Deathstar is near completion. Testing 2nd tier fire power
>ANH
Deathstar is completed. Testing 1st tier fire power. Gets destroyed.
>ESB
Planning/construction of 2nd Deathstar unbeknownst to protagonists/audience.
>ROTJ
Reveal of construction of 2nd Deathstar. Reveal of fully operational weapon. Gets destroyed.
The problem with the Deathstars is twofold:
They spent 22 years from design to completion on the first one. They spent 4-5 years on the second.
The Empire can't cover much ground with only one superweapon, so instead of having the second Deathstar being built as a consequence of the first one being destroyed, only to being forced to come up with new ones, larger and more difficult to destroy (not really), for each film, we should instead have a reveal in this new triology:
The first and second Deathstar were only two out of hundreds of Deathstars, that all were being built throughout the years between episode 2 and 4. When the Rebels destroyed the first Deathstar, the Empire was already far into the construction of the second one (eliminating the problem with amount of years it took to build,) and there's a whole brigade of Deathstars spread throughout the galaxy (eliminating the problem with how easy they are to destroy, since we don't see them as the ultimate threat anymore, anyway.)
I'd rather see a space battle involving a number of Deathstars, than the farce that was the Starkiller Base. The Starkiller should be revealed later in the trilogy, with several Deathstars guarding it, so that we would see the size comparisons as actual space stations onscreen, instead of a stupid hologram in a forced Resistance Base briefing scene.