Judo Throw Perk?

[JulianLW]

In Martial Arts, the Judo Throw technique notes that a judoka can throw for damage at Judo -1 for Thrust-1 damage.

I'm wondering what y'all think about a perk (I'm thinking it might be comparable to Ramming Speed) that allows a judoka to use her opponent's size against him:

Fall Harder: This perk allows a judoka who makes a damaging throw to replace her ST score with the opponent's regular (not current) HP score to calculate damage. For example, a small judoka with ST 8 could throw a large opponent with 15 HP and inflict 1d crushing damage instead of 1d-4 crushing damage.

What do y'all think?