Also, I tested the Razorback Hero Style RA today at a training dummy.
Wearing a 5.6 Celtic Spear with 99% quality
327 Strength
110 Quickness
no hastebuff
Of course, Heroes can't pull off that guaranteed-crit combo with vendo. Also, when hitting a real target, the damage will probably be much lower than 978 due to spec AF etc.
I have mixed feelings about those RA styles. If you can reliably burst a target down, they may be worth their hefty RA cost. On the other hand, reliably bursting down a target like this feels a bit lame. Especially as these RA styles only gain their full potential if you have low haste and low quickness. This encourages awful min/maxing like cancelling your haste- as well as dex/quick buff and unequipping any gear with +quickness. As soon as you equip a faster weapon or play a high quickness/haste character, these RA styles become useless.
Hence, one might consider changing the mechanics of those styles to some extent. As there is a 10 minute cooldown on these skills, the usual DPS-based balancing of style-damage should not be applied here IMHO. Thus, haste and quickness should not be taken into account when the damage of RA-Styles is calculated. Weapon speed might be considered, as switching in a special weapon that is extra-slow seems like reasonable micro-management that adds a tiny bit of extra difficulty. However, classes which do not have access to two-handed weapons are at a disadvantage in this respect (blademasters, mercenaries). Thus, it might even be adequate to also discard weapon speed for the damage calculation of RA styles. On the other hand this would render them almost equal to an extra Flurry-like instant DD with a larger cooldown ...
Balancing these skills is obviously not easy and maybe that is the reason why Mythic abandoned this concept back then when they re-designed the RA system.