Does "just as important" mean "(Mr.Kim's uncle is) also an important cause
to his own family’s dwindling sources of revenue"?Context:
The rout of his forces appears to have been the final straw for Mr. Kim, who saw his 67-year-old uncle as a threat to his authority over the military and,
just as important,
to his own family’s dwindling sources of revenue. Eventually, at Mr. Kim’s order, the North Korean military came back with a larger force and prevailed. Soon, Mr. Jang’s two top lieutenants were executed.
More:
http://www.nytimes.com/2013/12/24/world/asia/north-korea-purge.html?hp