So a level 8 re-charge power vs a 2nd level character in one edition is somehow comparable to a 1/8th CR ordinary attack vs a 1st level one in another?
I think my point was that unlucky low level PCs die randomly in any edition, even 4e - this was a published 4e adventure, though I reduced the number of zombie hulks from 2 to 1; either way a 6 level difference in levels is 'legal' under 4e DMG encounter-building rules. The only 'illegal' element was that the hulk's 350 xpv made it a
below-EL1 encounter (minimum 400 xp) for the 4 2nd level PCs.
I guess if you absolutely don't want PCs dying from damage then start at 3rd level and use only low-dmg opponents works. Or outside AL you could just say PCs can only die from failed death saves, not damage.