A few things to clarify and answer your question.
I refuse to use my 3 x 136HP LOH´s as it makes for very boring and die intensive duels. I could....but I don´t.
I could (but I don´t and have not needed to) take Paladin Attack Boost or even Better AC Boost (that you inlcude on your Human Barbarian example)
What I can and have used since I hit Level 12 is Dispel....man that messes up your #´s for AC, To-Hit and Saves hehehe
That Barbarians AC is Prolly 26 so to present that Human Barb is to throw him into my meat grinder
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(I doubt he´ll get more than 1 5th attack, 2 if he´s lucky and rolls right)
Can I hit a likewise built Tank, Not really, actually the whole point of my thread inputs is exactly that!
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(Thank you for pointing it out in a different way)
I have had several Duels where I´ve had to go without CE and Curse-Trip to be able to finish em off.
(Every build-Player is also a learning experience on PvP style.)