Akashic and Witch, and probably also Totem Warrior, are the hardest.
The witch is, IMHO, suffering from the fact that it was a pretty murky class in AE as well - nice flavour... but a bit like the 5th wheel - it dabbled a lot.
Akashic, well, I think an akashic could be a bit like a warlord, as you said, (remembering tactics) with some more supernatural, but subtle, abilities, like telepathy (reading memories of the last seconds and so on), giving it a bit of a more flexible slant (though he should stay the hell out of high-damage territory).
Totem warrior screams "builds" - if you adhere to the powers of your build (like the warlock), you get more out of it.
All this is assuming that one would want to keep the roles at all, since Arcana Evolved was a a way to remove strict roles per class...
I think the roles are a nice way to classify the main job of a class - in AE, the classes had also a certain niche, the warmain was usually the frontline guy and so on.
But, in the AE spirit of "more option, more choice", I think it would be better to do a more graded system - a class would get its main role, like 4E, but also gets powers to do well in the other roles, just less well. And perhaps a sort of "non-role", which it doesn't get - usually.
Under this system, I'd look at it like that:
Code:
[B]Class Main Role Non-Role[/B]
_______________________________________
Akashic Leader Striker
Greenbond Leader Defender
Mage Blade Defender Leader
Magister Controller Defender
Oathsworn Striker Controller
Ritual Warrior Defender Leader
Totem Warrior Striker Leader
Warmain Defender Controller
Witch Controller Leader
Unfettered Striker Defender
EDIT: By these "extra roles" beside your main role, I that your powers should tend to gravitate to these roles as extra to the normal effects. For example the warlock in the PHB has a controller-ish slant, if he goes fey (messing with them) or infernal (area effects). In that way, classes should get about four powers per level, two "pures", and one with a slant to the "sub-roles".
That would allow picking up these extra roles relatively painlessly, without compromising the main role.
Cheers, LT.