I go first for the movement, then straight for night battles. By that time you're likely to be facing multiple stacks, and attacking them one by one is vital. In my last Shimazu campaign, when I neared Kyoto there were about 3 Yamana stacks, 6 Takeda ones, and a stack of Hojo or 2. The Takeda especially were just moving along slowly in a tight clump... I had to gradually attack them when one got somewhat separated from the others, so the + movement and night battles were vital. I ended up gradually whittling them down, but it was a real struggle.