Interesting. I read it as:
-Everybody and their brother from the surface tries to steal the crown with robot soldiers.
-Many of these robots slaughter mimigas, for whatever reason--possibly at first a few used excessive force in trying to get the mimigas to lead them to the crown, in vain, which escalated as unprovoked acts of international violence tend to do into a full-fledged war.
-Robots are very much winning this war.
-Mimigas, now desperate, use red flowers to give them an edge in war, keeping them from being obliterated.
-Miakid finds the crown. After perhaps trying his defenses once or twice, other robots go home, objective no longer obtainable. His robots likely become ignored in favor of new minions.
-This whole time Curly and Quote have been trying to destroy the crown before it could be claimed. Now that it's been claimed, there's even more pressure on them to do so.
-Miakid wages war on the surface with his new army of monsters.
-Curly and Quote try to stop Miakid. Their degree of success is unknown, as Curly can't remember the outcome and Quote remembers nothing at all, but they at least wounded and possibly killed him at the expense of both having the crap beaten out of themselves, Quote even worse than Curly. Curly wakes up some time later with no memory and lives quietly in sand zone with some mimiga children, while Quote spends the next ten years performing some sort of automated repairs (alternately, he spends the next ten years simply dormant until an intercepted signal from Kazuma to Sue happens to pass him and trip some flags, him waking up).
-If not already in the previous step, Miakid dies.
-Nobody tries to claim the crown (at least not militarily or successfully) for ten years. It is unclear if this is because they thought it was destroyed, they were recovering from the war (unlikely), or some treaties sprang up which meant anybody who tried would be bombed to the stone age long before they got it.
-At some point in the interim, Arthur defends the mimigas from the red demon.
-Date, getting to the island in the company of a group of researchers and possibly with some inside information, gets the crown.
-Date disposes of the other researchers (or at least tries to) and attempts to get his hands on the flowers so he can repeat Miakid's war.
-Quote wakes up and begins mucking things up. He stirs Curly into action too, or at least enough action to draw Misery's attention, which REALLY spurs her into action.
-Date finds the flower seeds and begins trying to produce a usable crop as quickly as possible.
-Date also does research on the flowers, and finds a way to get their effect to work on humans too. Needless to say, that's a nasty weapon.
-Just as he's in the final stages of preparation, Quote reaches Date and kills him. With some effort.
-Quote and Curly may or may not be contacted by one of the enchanted talking dogs that they need to kill Ballos, and if so go on to kill him, destroying the crown forever. If not, they likely assume it is destroyed along with Date, as does the world at large, possibly for a long time...
-Interestingly, that last point means that other than losing contact with that one small research group, the surface world may have never even known there was another attempt at stealing the crown. At least not until after the fact, as surely they'd have some contact with someone on the island eventually.
My thinking is that the fact that Misery can transform humans into mimigas suggests that the mimigas were artificially created and introduced to the island, by Misery, far in the past. Why would she, or her master at the time, want mimigas? Because she also created the red flowers, which could turn them into vicious monsters to be set lose in enemy territory. That would imply that the flowers have been around as long as the mimigas, which is longer than any of them can remember. Remember, at some point in the past there wasn't even a floating island, so everything on there had to be added at some point, and we are led to believe there's no mimigas on the surface. The only alternative I can see to this one is if Jenka made the mimigas to populate the island, possibly feeling bad about how empty and desolate the island was and feeling lonely as she needed to stay there either to guard or to comfort Ballos, but that's not my personal theory.
Also, you left off an important part of the conversation in the plantation. Specifically, the part which includes something like "But we were different. We were sent here to destroy it." Since you've obviously got a save right there, could you post the rest of that speech? I'm sure it'll support one or both of our sides.
