They spend half of a episode celebrating a single goblin kill... and that is only one of the many bad time consuption in Grimgar. If a anime wants to be slow its okay if its done in a meaningful way, so anyone who is watching doesnt want to drop it as fast as possible, Fate/Zero and Steins Gate, for example, have kinda of a slow start and still is good to watch because there is important things happening (Fate) or Funny and some serious things (Steins Gate), grimgar doesnt do it.
Oh and that tragedy was the most obvious thing ever
