A Swordsage has free Weapon Focus, lots of boosts to help his to hit chance (like Distracting Ember, for an automatic flanking buddy) and maneuvers that can hit touch AC or leave the foe flatfooted to the attack. Similarly, Clerics have buff spells, Druids have Wildshaping into high str forms, Bards have some buff spells and Inspire Courage, Rogues can reliably get a foe flanked or flatfooted (at least a Rogue that wants to survive fights does)... Generally, all medium BAB classes that are intended or can go melee get some means to make up for their lower BAB compared to a warrior class. What do Warlocks get to help them?