The drastic reduction in attack speed and the oGCD that enshrouded attacks give makes the enshrouded attacks' potency per second value dwarf regular gibbet and gallows. You're hitting at a 1.5s GCD, which is insanely fast for this game.

Also I'm not at the pc to look but Lemure Slice is the oGCD that enshrouded gives yea? Its a bit...extremely wrong to compare a GCD's potency to an oGCD's. Globals have opportunity costs; if you use harpe, you're not using any other GCD for 2.5 seconds. Lemure Slice doesn't trigger the global cooldown.

Not saying reaper doesn't need buffs, but I don't think there's a solid understanding of how FFXIV works in the examination of its problems.