One goal of christian missionaries was to break up multi-family units within native american tribes since these were common in matrilineal societies and gave too much authority to older women in the tribe.

This is TRUE

The early christian missionaries in North America had a stated and deliberate goal to break up the multi-family units within Native American Tribes.

The idea was to eradicate a system where older woman in a tribe held considerable power and authority. 

For European Christians, this system was seen as anti-christian, barbaric and backward.