Aircraft, ship and military equipment identification of all sorts, is a very specialist field, and needs to be both taught and studied extensively for people to build up the skills necessary. At the beginning of WWII in Britain you had the Battle of Barking Creek were two formations of RAF Fighters attacked each other. And the channel convoys were notorious for opening fire on any aircraft that they saw irrespective of which side it was from. It was only with the introduction of training of aircrews that the situation improved, and RAF pilots could be trusted to not shoot their own side down 90% of the time. Things were so bad that by D-Day the Navy couldn’t trust the numerous crews on the ship not to open fire at anything with wings, and given the large numbers of aircraft that were going to be flying around, this was a major problem. The solution to which was to take a large number of older men who were members of the ROC, Royal Observer Corps, who were experts at aircraft recognition, these guys could at a glance tell the difference between ours and theirs. And could normally given a good look tell the difference between various Marks of an aircraft, again from either side. These men were taken onboard ships of the invasion fleet, and unless they identified the aircraft as hostile, you could not open fire. There is no question that at a quick glance, while under fire, the difference between POW, Repulse and Exeter are not so obvious, all three have two turrets forward and one aft, and all three had two funnels. Which given a brief glance by an aircrew suffering a significant emotional moment, could easily result in confusion. The only outlier was Cornwall which had two turrets forward and the same aft, with three funnels, which made her distinctive, of all the ships in Force Z. Yes a long service man from the pre war British Navy might be able to tell you what class of ship he was looking at, if it was British, and might have a good idea when it came to German, French and Italian ships, but unless he had served in the Far East or on the Caribbean station, he was unlikely to have much of a clue about Japanese or American ships. It’s only the ultimate nerds, who spent their life studying ships who would have any idea about a random ship that they have seen. Most people relied on looking a ship up in Janes and that is why virtually all naval vessels carried a copy.
RR.