So why do Nissan and other companies name products “Armada” after a spectacularly failed fleet?
The word "armada" is a generic term for a fleet of warships. This applies to more than just the "Spanish Armada".
The Japanese word "kamikaze" means "divine wind" and refers to storms back in the 1200s that destroyed Mongol fleets that were threatening Japan. If the weather is on your side you don't need military superiority.