I like Satorl Marsh daytime a lot more than its counterpart, it's my favorite track from 1, I'll say.
If the themes are good but they suffer from being in a formula, isn't the original guilty of the same thing, then? Gaur Plains is just like you say, and the dynamic with Satorl Marsh was just inverted, though both songs seem different, that I admit, which is exactly what happens with Sword Valley as well. However, many of the overworld themes nonetheless still function a lot like the other two games. That makes me think you still judge the tracks a lot based on their individual merits, and not exclusively or primarily on how unique they make the soundtrack as a whole. Your last sentence in your first paragraph makes me think I could be misunderstanding somewhere, but I'm not sure.
You did misunderstand, yea.
"but when I played 1 I remember finding the dynamic of the day and night themes a bit generic."
That entire comment was pretty much about 1 :) . In fact, that is why I specified Satorl Marsh daytime. Even though the nighttime theme is beautiful, it feels like one of the least inspired dynamics in the whole game.
Regarding the area themes, I do remember 2 having good ones. I'm just saying in general I don't think the music in 2 is as good as 1. However, it has been way longer since I've played 2 (aside from the tutorial), so take that with a grain of salt.
And for me, 2 paling in comparison to 1 doesn't make it bad. In this case it still resulted in really good music. But I'd prefer it didn't even warrant the stylistic comparison to be honest, because when it does 1 usually wins.