I wouldn't try to make sense of a "story" in the first half of Idolmaster; devoting an episode to every one of the 13 idols isn't going to leave much space for that kind of stuff. Call it pandering if you want, but I liked how it turned out.
Also yeah although the finale song really grew on me I was expecting a bit more than a montage lol
Well, yeah, but the quality of the filler compared to first season was pretty laughable. Obviously the story arcs are loads better than first, but First really drew you in. I suppose it was more fun seeing them make their debut, but the quality of the fillers didn't have to suffer in compensation of better story lines.
Just finished Idolm@ster.
What animes should I watch next?

Welp, Milky Holmes next, I suppose.