Tactics for playing against Wizards.

Ideally, in our build, we have a perk in the luck branch that gives 15% resistance, plus the unique aura = 45% resistance to archers, druids, and the uniques themselves:), and also to treants. It's even better if you also have boots with +10% (although if you have boots with speed, those are better). So, the magic resistance is quite good.
Who to put in the sworn enemies list depends on the situation, but in principle, DrNick is right.