In the same shaft design, from the same manufacturer, you'll generally find a 10 cpm butt CPM difference between flexes.
Across manufacturers or designs, all bets are off.
In The Modern Guild to Golf Clubmaking, here are the posted RANGES for shaft flexes in graphite wood shafts
L - 220-254
A - 219-257
R - 216-277
S - 235-295
X - 261-308
So I ask you, based on this chart, what flex is a shaft with a butt frequency of 250 cpm?
Let's suppose I have very little technical knowledge. If I'm reading that correctly, senior flexes a bit more stiffly (relatively speaking) than does a women's flex shaft?