Not so JellySlayer. The class most likely to win does not necessarily live the longest on average.
GE Wizards, if they die, tend to die early on, therefore bringing their average "lifespan" down.
Orc barbs, are less likely to win than GE wizards. However, their common deaths are mimics, aging, dopplegangers, DH, molochs, chaos guardians, etc. Their deaths tend to be further into the game. So their "lifespan" is longer tha GE wizards.
A GE wizard may hit a couple block traps and firetraps, dying eachtime, before getting to DT, from there being hard to stop once morgia training has started.
Orc barbs will reach DT with more consistency, but are not home free like the GE wizard.
Basically, orcbarb will life longer before the he croaks.