I am not sure you have taken into account a Steelsoul's synergy with the Fighter skills. For 96 XP in Fighter Skills (3 Weapon Prof, 3 Parry, 3 Slay, and 3 Improved Slay (alternatively, the 3 Slay/Improved Slay could be spent on 2 Eviscerate, 2 Stun Limb, and 2 Resolute)), +50 for Steelsoul 5...