There are probably very slight differences in the attack charts. They hand tweeked the damage and crits more than once during Arms Law's life. The closest thing I can think of to a big difference was the 00 E Slash Crit (the groin shot crit). IIRC correctly, in the old version, the victim survived it in a terrible ironic punishment. In the RMSS version, they added a death result. I don't know what version RMC uses. Also, I'm not POSITIVE I remember the old charts correctly, but that result was always a legend in my groups (which means it's possible that we willfully misread it).