Look at the "Harvest" in units 1 and 2 (Bayfield and Douglas counties). The pitiful numbers for the last few years have dropped directly in proportion to the massive spike in wolves.
The rest of the state has been affected, to a degree, but these counties have been absolutely devastated,
Escalating wolf population is certainly taking a toll. I hunt in DMU 6 in Bayfield County so I can attest. In addition, the rising wolf population is coupled with a herd that is intentionally being reduced, and aided by two consecutive bad weather years that surrounding states experienced also.
I might add that the two northwestern units you cite are no where near as bad as some of the northeastern units.
Not to mention that the wolf problem is basically out of the hands of Wisconsin's DNR.
