brief summary of what’s up:
it is almost unanimously accepted that the ancients were human
there are enormous ancient creations called ‘towers’ which serve more to control the environment rather than keep humans specifically alive. they do such things as control the weather and even create bio-engineered creatures to keep certain populations in check (such as humans). in the opening movie to the first panzer dragoon you can see a couple airships hovering around one of these towers.
there are other creations called drones which are like the bio-engineered creatures, except they look like humans. they usually have a function that pertains to the activities of certain ancient ruins and sometimes even the towers.
the empire is the most dominant population of humans, they excavate ancient ruins and reactivate the weapons that they find. at first they used these weapons to defend themselves from the bio-engineered creatures but then as part of human nature, they became ambitious. they used their weapons to attack other populations of humans and claim their land and resources. there were a few other factions that also had the idea to use the ancient weapons, but they were all destroyed or annexed by the superior empire.
the seekers are a nomadic group of people that will use ancient technology, but only to destroy ancient technology. they want to destroy all of it. they are enemies of the empire because they believe that the empire is unearthing the same things that nearly destroyed the world 10,000 years ago.
in the first three panzer dragoons you were trying to destroy the towers, this would give humans a chance to live in freedom rather than having their world be controlled by their long-dead ancestors.
i’m sure the others will have more general information to add 
as for your theory… i agree but for different reasons. the empire has advanced a great deal in the series despite being brought to its knees time and time again. before they were able to harness the power of a basic ancient technology called “float engines”. they dug up these float engines and attached primitive ballistic weapons to them. later on they discovered how to use the incredibly destructive ancient weapon technology as well has how to create float engines of their own rather than having to use the ones they found. they continued to research all of the ancient munitions and experiment with creating their own. in panzer dragoon orta we see that they have even developed anti-laser shielding (an incredibly rare feature even for the ancients). they also have created a near equivalent to the dragon and while the dragonmares are still trumped by true dragons, they can be mass produced and nothing short of a dragon really stands a chance against them. now we don’t know if anymore dragonmares will be able to be produced but just the fact that the empire can create things that are almost as powerful as the strongest ancient weapons shows just how far thy’ve advanced. in one document in PDO’s encyclopedia it said that the empire controls most of the continent now and i’m think that in a future PD game, they may control even more…
sorry for the long post, you’ll notice some of us here start writing out an idea, get carried away, forget what the original topic was about, keep typing, finally realize how much they typed, and still hit ‘submit’ anyway. 
welcome to twota