Personally I don’t believe the name change has anything to do with “upsetting the French” as it’s a medieval battle & keeps the history for both nations alive. The French would just name a new ship or sub “castillion”
The more likely reason are
Agincourt is a place in a different nation.
Achilles is smaller from a font size so cheaper costs in terms of text & branding (eg cap bands)
Ajax was the original name so a civil servant for a perchant for Greek myths wants to go back to that theme.
Or perhaps the boat just has a dodgy starboard propeller
Manages to 1 for 1 swap my tatty old wooly pully at an army barracks. Sad to see it go as it was even older than me! The new one is much less scratchy though
