It seems to me that the best way to balance the new classes and get them to "comparable" power level with the existing classes (comparable being a relative term) is to fully optimize them and then use optimized builds in scenarios. Ideally the new classes would be played through the same scenario as similarly optimized builds of established classes. The new classes could also be substituted for the old classes according to their determined new roles.
So, my question is this: who else thinks this should be done sooner rather than later and would be willing to give it a preliminary shot?
I started a recruitment thread in the PbP forum for a mid-level playtest. I'm on my phone so I don't have a link, but you're welcome to submit your most optimized build and give it a go.
What level(s)?