The former suggests working with complementaries (putting together energies which complement oneanother (like Fire and Air) to enhance or encourage whereas the latter works with opposites (day and night, hot and cold, Fire and Water) to counter or bring balance.
The former would be like sprinkling sugar on a doughnut, the wind that whips up the wild fire or the rain that nurtures the plant growth. The latter works by countering and balancing - rain that puts out the wild fire or the sun that dries up the waterlogged ground.
The associations made and their opposites on the circle of the year (medicine wheel too) by changing these two positions therefore suggest the two different ways of percieving and working with these energies. Nurture or counter.