Shoha will sadly not fix the whole sam issue but it will at least help us deal some more damage. The real issue is that our rotation is based on a specific SkS tier and having 100% boss uptime in order to not delay our burst. Fixing this will also help Sam get on the upper end of the melee job.
As for Dragoon, I keep saying that it does way too much atm, damage, buffs... Imo, if Monk's brotherhood was a general damage buff and not only a physical buff, yeah then Dragoon would need to be above. Atm however, I don't think that's the case.
I personally think that Sam should be way higher than it is right now, followed by Monk, then Dragoon and Ninja roughly on par. (Can't speak about ninja tbh, I don't have played the class at all :x )
That, and buffing some ranged dps and casters would make for a more healthy game balance overall...