Rolkatsuki

So from what you see above is I dig up for ideas for what France might have in their submarine line in the future and compared them to equal tier WG announced submarine classes in terms of their historical specs.

Minerve: a class of french submarines build from 1931 and saw service from 1936, 6 of these where built of those only 2 survived WWII. Interesting note: One of her rear torpedo launchers (not mention in the above table image) appears mounted on a swivel mount so she can fire that launcher even while side on to the enemy

Aurore: the last french sub class to be built, launch and saw service before the outbreak of the 2nd World War. Of the 15 plan to be built 7 of them where completed 1 before the war and 6 after it. Interesting note: One of her rear torpedo launchers appears mounted on a swivel mount so she can fire that launcher even while side on to the enemy

Narval: a post WWII class that incorporated features from the Type XXI U-boat and improved upon them. 6 of them saw service from 1958 none were lost in any conflict. I won't be suprise if WG chooses to make a fantasy sub over this considering its many years advance compared to Balao and U-2501

Guessing national flavour of french subs: looking at the displacement this translates to poor health pool compared to the others, above average to high submerged speeds and heavy torpedo weaponary and from the dimensions above average agilty/concealment. What we have here is a line of skirmish flanking glass cannons. Also very convenient rear torpedo firing arcs(nearly Graff Spee levels)