170 str lk with megin, blessing, concentration and auto-bersek gets ~825 atk. If the ennemy is using thara and such, and that the lk is using a quad bloody weapon, the damage output will be roughly the same as the atk + the skill modification. You get 9,9k bowling bashes, spamable with aspd delay, and that are area of effect.

Megin not being unbalanced? lol. 19,8k, with a pally double atk bonuses, and with the + 20 stats, probably 22k with.
- Look, an ennemy squad! 
*Lk use one bowling bash* 
- Wich squad?
Something like + 10 str, would still be godly imo (2.5x times the best bonus a single regular accesory can give), but wouldn't unbalance the game. Giving four + 10 str accs, with 200 weight instead of 800, would give something still godly to a guild leader, but not breaking the game balance.