Why replacing weak officers may not fix a war effort

Would replacing Spain’s worst flag officers greatly improve a later European war?

Probably not; the force’s systemic problems, particularly logistics, would require far more than a few personnel changes.

Alternate-history fixes that focus only on personalities miss Spain’s wider institutional difficulties. Even if Spain replaced some especially weak senior officers, its logistical problems would remain. Those problems were too extensive to cure by changing a small number of commanders. Individual command performance mattered, but the administrative system still determined whether forces could operate.