I may just be doing it wrong, but it seems like Extra Stats doesn't like formulas for Enemy xstats. I've put in formulas such as this:
:satk => '0.5 * mat + 0.25 * mdf + 0.25 * luk',
which are the same as those for the player actors. When using the same skills reliant on xstats, enemies never deal damage, while players do; even setting an attack to merely 'a.satk' or such does nothing for enemies, while dealing the xstat in damage for actors.