I would need the two excerpt to answer confidently, but as far as the two stories as a whole, "Grendel seems comical and ridiculous in Beowulf" considering that the soldiers all laughed with delight when the defeated him, "but he seems calm and calculating in Grendel" he sneaks into the passage at knight to kill many men in their sleep. Grendel and the men thought that he was an all powerful monster, but Beowulf proved to be stronger, humiliating the once confident monster.
"Grendel seems comical and ridiculous in Beowulf, but he seems calm and calculating in Grendel" is the statement that best compares the two STORIES.