Tome of Battle Doubt

[Behold_the_Void]

You track maneuvers separately for each class. Your initiator level increases by one for every two levels you have in another class. So, your Initiator level for Warblade is 4 ( 3 warblade + 1.5 for crusader, rounded down) and for crusader it's the same. You are greater than the sum or your parts.

As I recall, you gain full initiator levels from another initiator class, so Warblade 3 Crusader 3 has initiator level 6.