Can I use a maneuver to meet the prerequisites for a martial stance, then swap out that maneuver later?

Question

I'm a Warblade in the process of reaching level 6. I have one level 1 Diamond Mind maneuver. Is the following possible:

For my level six feat, I want to take Martial Stance to attain the Diamond Mind stance Pearl of Black Doubt. It needs one Diamond Mind maneuver as a pre-req.

Can I take that feat and add that maneuver, the swap out that maneuver for one of a different school as per the Warblade leveling rules?

Answer 1

Advancing a level has an order of operations

This order is detailed in the Player's Handbook (58-9), but it's absent from the SRD so that Wizards of the Coast can sell you books. What you need to know from it is this: class decisions are made before feat decisions.

Thus, this warblade must use his ability to learn a new maneuver in place of an old maneuver before picking as his level 6 feat Martial Stance, and, were the warblade to've ditched that lone Diamond Mind maneuver, the warblade can no longer meet the Martial Stance feat's prerequisite for taking the stance pearl of black doubt.

However, once the warblade knows the stance pearl of black doubt via the feat Martial Stance, because "[s]tances are considered maneuvers for the purpose of fulfilling prerequisites for learning higher-level maneuvers, or qualifying for prestige classes or feats" (Tome of Battle 43), the warblade can safely swap out (perhaps at level 8?) that other Diamond Mind maneuver that he used to meet the Martial Stance feat's prerequisite and continue to meet the prerequisite for the feat Martial Stance and the stance pearl of black doubt with the stance itself. (Note that this—that is, meeting a feat's prerequisite with what's, essentially, the feat's benefit—does make this DM a little queasy, but it's not like the warblade's casting spells or anything, so whatever.)