Yeah, my interpretation of Harry's stats is that he bought some Might and got Inhuman Strength. That pretty much covers that level of strength. 400 kg is...good, but just borderline inhuman, not completely outrageous.
And I firmly believe he has Toughness as well as Recovery, if only to represent the ability to completely ignore pain thing, and how much more iron messes him up than other stuff.
As for Cat Sith, it was his ability to just grab full Sidhe and take them away with him casually that made me think "He's way stronger than these people." and led to Supernatural on Strength.
And Toot-toot seems good to me at Great Weapons, that'll let him butcher pixies pretty well. I'll think about Wall of Death, but minions don't necessarily count enough for that Stunt to be needed, IMO.