The other way around. Shining the Holy Ark takes place twenty years before Shining Force 3. It explains in more detail the whole Vandal/Innovator thing, takes place in Enrich, introduces Galm, and has this.
Ah, interesting! It plays like Shining in the Darkness, right? I never got into SitD, but if StHA is a lot better i might try it. I couldn't get into the dungeon crawler pen & paper grid map gameplay of Darkness.