Does anyone know if I can divide a clump of Indian Summer? Or should I leave it be?

I received 2 little seedlings at last spring's plant swap, which gave me the most gorgeous blooms last summer. I didn't expect them to over winter, but they did & it looks like multiple stems in a clump now. Are these stems actually from the root of each single plant or are these multiple plants now that I could separate? I don't want to risk killing it... but I'd love to spread them out for a really great show!