Erm, no it's not. It doesn't say you get 150+150*(MP * 4)....
It says 150*(MP * 4)....
Also this is not a heal ability, it is temporary HP...that lasts a minute...
Telling someone that a multiclass bard is not a Bard, and then suggesting a multi class barbarian is a barbarian.......I'm at a loss for words.
Also I'm fairly certain that Zoda who created that Dwarf build did hit over 2k HP with that build in Unyielding Sentinel, as you have done. I'd have to ask him because I don't know for sure but if memory serves me right he did hit that mark. With stance.
Also what is your barbarian build? Which ED are you using? I run an 18 Barbarian/1 Favored Soul/1 Fighter in Divine Crusader that has Death Frenzy and Tier 5 Ravager. Has very good survivability and DPS is pretty good, but not better than Paladin. Not sure how it stacks up to Centered Kensai. It's at least close.