Are there any factions that are clearly over/underpowered?

As a follow-up to this question, my initial impressions/readings suggest Wild Walkers lose out in mid-late game (but maybe can secure an early advantage?), whereas Drakken/Vaulters/Ardent Mages are seen as powerful.

Is there a fairly wide consensus in the community? Maybe not an overall ranking, but usually people agree on the extremes. Feel free to link to well-written thoughts/discussions on the matter.

Thanks!