I have lots of Russian Sage too, and I am finding that it can be very dominant! I almost wish I hadn't planted it in my flowerbed. It is kinda huge and sloppy. I made a wooden fence to put in front of it to keep it from falling over onto my other flowers. A lot of people comment on it, saying it's beautiful - even though most of them think it's Lavender.
I know I will need to divide mine sometime, I am not looking forward to the job! It is a messy, although beautiful, plant.