Originally Posted by DoubleGJ

There is a stable timeloop created by the events of JJ2. Because Devan went back in time and attacked Carrotus centuries ago, the Galactic Rabbits fought an uneven battle (well, uneven if it weren't for Jazz & Spaz) and their civilization's advancement was slowed. They did, however, advance unnaturally in militaristic fields. This is why in Jazz's time, royalty lives in an old-fashioned castle surrounded by far-reaching fields untainted with urbanization, BUT at the same time they have weapons compatible with Turtles' ammunition. Devan himself unknowingly made his nemesis a threat.