Re: dueling editions - just saw this floating around earlier today:
It's not this exact case, but one like it, in which there are two sets of conflicting rules in the same game edition. Pick what you want. This makes sense, as people who bought the first publication might not have the opportunity to get the revised version, due to whatever reasons. What would make the most sense from a tournament's perspective is if you're going to use something from a specific source, everything you use has to be from that source, ie. no mixing Green Tide with anything that comes from W!G v.2.
Considering the shenanigans that a lot of other armies can pull, like admech being able to draw from three seperate books simultaneously, this doesn't seem like a complicated solution.