had the same problem Umber and Kraxis both hat several champs with sword of wrath etc...
cheap workaround (which works pretty well against anything, apart from heavily armed opponents):
at the time I was focusing research on civ and warfare, the latter mainly on cutting weapons for my sov (wanted the kar.. whatever the blade with +dodge). I didn't have much troops but a rather good equipped sov who could handle almost anything. the first time he (alone, as usual) got into a fight against 2 champs with those insane weapons, I just made sure they won't reach me and still have AP to hit. I've killed them each with one or two attacks (14hp - haha) and only getting hit once (which was as much as I could handle. If you can't, get an assassin with dominate). anyway, after that I focused on dodge and researched the dodge+50% tactical spell. Its still a pure game of chance, but now I win those battles relatively reliable, so reloading isn't necessary too often (I only lost 1 battles of 6 anyway, which was against 2 champs & the sov who even tried casting on me *g*). Even though dodge might not be quite as useful as armor as of yet, in this particular case its way better and works pretty well. plus, you don't have to research armor to soon - saves metal in unit production which, in my case, was necessary as I had no mines near my starting loc.
hope this helps until the bug is fixed
Ora