Murume!
I do not have both types, just the Euphorbia flanaganii. Looking at other photos online, it seems what you have there is Euphorbia woodii, the leaves seems to cluster and grow thicker and tighter. Euphorbia flanaganii seems to have slimmer leaves and growth swirls a little looser around. But I do not have both, so I can only see it on the point of view of looking at my Euphorbia flanaganii.
