@zeroxjac I feel like the show slow pacing is factoring the skipped contents, there were plenty of unimportant things (I can't put my hands on what it is unless I watch it again, though I think it was something akin to showing Rimuru and others just standing around) that could done quicker or skip all together, but for some reason they just went on a roundabout way to show it.
The anime trying to cover like what? 11-12 vol worth of manga as materials with 25 episodes?
Shouldn't it hurried it up?
The Milim arc start halfway through vol 6.
In the case of covering 12 volume worth of manga with 25 ep, shouldn't Milim appear like.. Around the end of ep 12?
But no, she appear much later, which is ep 16, which is 4 more ep than it should (well what I calculate at least).
Then maybe, when they realize that they haven't cover enough stuff of the material halfway to the deadline, they try to speed things up so they manage to cover the whole, which is why there's plenty of skipped content.
But you know this dividing is just my perspective from the one that read the manga, not the novel one (light or Web whichever it is).
Tl;Dr
The pace is slow, when the studio almost facing the deadline, they kinda rush things over, hence the skipped content.
Though I got to give the studio credit since.. Again, they are trying to cover 11-12 vol worth of manga.