took my lvl 46 inv/stone testsubject, respeced him dry from slots in the attacks went to atlas to whack hellions in order to fill the blank in the BI for seismic smash.
Oddly enough i came up with different readings on the last decimals on everything posted in the beginning of the post.
Testsubject lvl 1 hellion minions.
0-enhancements in attacks.
Brawl: 88.21---->1
Stonefist: 245.05---->2.7780
Stone mallet: 401.89---->4.5560
Heavy mallet: 558.72---->6.3339
Hurl boulder: 401.89---->4.5560
Tremor: 245.05---->2.7780
Seismic smash: 872.4---->9.8900
Strange that lvl seems to differ...