Poorly written but I read it as being three different limitations:

1. Six fish total.
2. of which only one can be a wild coho
3. and up to two adults.

Another permutation is whether the one wild coho includes jacks? Taking my interpretation it would.

Guess that is what WDFW produced in an attempt at brevity.

As to conflicts between the WAC and the regulation pamphlet while the WAC is the law the pamphlet is what WDFW puts out in huge quantities for use by its licensees. If there is a conflict between the two I would opine that a judge would put the responsibility upon the writer (WDFW) rather than the individual who relied upon the erroneous language in the pamphlet.

And, no, I am not an attorney.