How is he any better than Holl though? His defensive metrics are very similar to Holl's in similar usage (and that includes a really bad stretch for Holl which he has since rebounded from, so Holl's defensive metrics are likely better than his) and his offensive metrics are significantly worse.
Plus he is a rental, which is not ideal for what the Leafs likely want. I would rather him than most other rentals at their alleged prices (Chiarot, Manson, etc.) because he is worth a 3rd round pick at most, but he likely doesn't make a difference in our chances or improve our defense all that much.