I don't think damage scaling is "broken" per say, but it is definitely unbalanced. Also, the size stat increases everything far faster than any individual stat. As the broken sword pulls from 3 stats at a scaling tier of "C", while the blesser, bat, roundel, cat ear fetish, barrel, and empty barrel all pull from a single stat. For me, the broken sword does 237, bat/blesser/roundel all do 55. Empty barrel of tier "D" does 27 while barrel of tier "A" does 137. My second playthrough I used two broken swords upgraded for XP boost, then moved onto the size sword as that does even more damage plus both have better abilities.