Pity about the Panzer Dragoon OVA. I watched it and, indeed, it's crap. The music was the only redeeming value. I wonder if Yoshitaka Azuma (the composer) did anything else...
Yeah, I'm pretty sure Mahou Shoujo Lyrical Nanoha and Maria-sama ga Miteru were made before the doujin shmups, just like Azumanga Daioh predates the Chiyo/Osaka themed 'Tiyoruga'.