Tip for anyone who didnt played beta and somehow want to be semi competent in the game -spec your team in one damage only, either magicka or physical. Dealing both damages is useless, its better to have a mage for CC, and rest physical damage dealers. Or otherwise full offensive spell mage team, plus one tank to aggro melee mobs.
Yeah I'm very glad I made a ranger + poly two-hander + death knight tank and then a healer. The last one was supposed to deal magic damage with Aerotheurge but I rarely use it exactly for the reason you describe. Another unfortunate byproduct of an armor system that hasn't really been thought through.
On the plus side, the Necro-Knight works perfectly. Dealing damage with with weapons leeches life due to the Necro passive, and this also goes for Retribution meaning: enemies hit you --> you deal Retribution damage --> you get healed. Using Blood Rain for massive Health Blood Suckers is nice (biggest heal so far is 205) and a staggering amount of Necro-spells (like Pain Shackle or whatever it's called, Bone Cage and Death Wish) really go well with the Tank play style.
Respecced out of Leech though, it does too little and you don't really need it. Oh and the Hydrosophist point you need for Blood Rage isn't wasted at all - Restoration and Frost Armor (or whatever it's called) are really nice, the latter cures tons of bothersome status ailments regardless of your Intelligence.
I suspect the build would be much, much better with a two-hander, but it seems fine with sword-and-board as well, you become pretty immortal.