I'm not actually that familiar with most of these , but I'll have to check them out. (I'm listening to "The Quest For Rudra's Mines" at the moment, which gives me high hopes for the rest of the score.)
I think Lufia 2 has a couple of leitmotifs shared between tracks, but they probably aren't used often enough to classify as a "main theme". (It appears in "Rumbling" at 0:55 and "The Strongest Man" at 0:46. At 4:10, there's something that sounds similar in "To the Future", but it's not the same.)
Tactics Ogre isn't something that I've listened to extensively, but it seems to fit the style the Hitoshi Sakamoto is best known for now (his other SNES JRPG works I've listened to, like The Adventure of Hourai High and Treasure Hunter G, don't use leitmotifs that often as far as I can recall). It's probably the most important soundtrack he made for the system, since its style has the most influence on his later works.
As for lesser known JRPG music for SNES that I like, Motoi Sakuraba's Tales of Phantasia is nice. (A friend introduced me to Hiouden recently, which I haven't listened to much of, but sounds like it could be good from a few tracks I've listened to.) Treasure Hunter G is good, too (and might interest you, seeing how, like Tactics Ogre, Hitoshi Sakamoto and Masaharu Iwata both worked on it; assuming you haven't already listened to it). Albert Odyssey 1 and 2 aren't as memorable as the Saturn game in the series, but they have some nice calm tracks, as well. (Thinking about 5 lesser known SNES JRPG soundtracks that you haven't mentioned already was a bit of a challenge, so that probably a sign I should listen to them more often, haha.)
Anyway, I'll have a listen to all of these (aside from Lufia 2, since I'm already familiar with that) later, hopefully. Thanks for the suggestions!
RE: Five Lesser-Known JRPG Soundtrack Favorites from the SNES