check ghost hunter shadow hunter skill description: "Critical Damage for standard attacks at the front -30% "
this makes all dmg from the front get a -30% modifier. stabs, everything. Shadow Reverse works correctly from the front because it teleports to the rear and stabs in 1 motion, it cannot be avoided. but if you use form the rear, it teleports to front and stabs for -30% dmg. go test on an npc in town. use skill from front and rear, see dmg dif is 30%
if you compare a spoiler great luck 30% passive pve bonus, with no negative effect from their luck coin of maphyr flip, and you can have a 60% swing in dmg to the front in a place like toi.
regarding the 2 plunders. 1 is AoE and low skill power. this skill is worthles. you also have dwarven flare bluff. also useless. the spiler plays like a dagger, it just has no front penalty and a passive boost for pve.
heartbreak, chain, blood stab, there all work the same unless you compare to a TH where heart and chain can reset.