Specifically regarding Antioch, the Crusaders were definitley not 'unifed in purpose'. Other leading Crusaders disputed Bohemond's claim as 'Prince of Antioch'.

But, there was such an anarchy unleashed in the region at the time that Bohemond basically squatted in Antioch while the other Crusader elements and Byzantine forces were busy pursuing different aims (securing the Cillician borderlands, marching on Jerusalem).