Yeah... but Iron Heroes was also a recalibration of the 3.5 game. Namely hit points and combat abilities for characters and monsters. (It looks suspiciously like 4e under the hood.)Mind you, I remember the arcanist being universally panned at the time, as an unbalanced afterthought, so I'm not sure that it would be too good a model to follow!
Cheers
If you dropped an Arcanist into a 3.5 campaign, he'd rock compared to a Wizard or other class. On the other hand, the Arcanist doesn't stand out hugely compared to other Iron Heroes.
I think the Arcanist would be somewhat underwhelming in 4e, and possibly needing a little tinkering. (Reduce starting power points... but allow bursts earlier.)