I can honestly think of a few worse & horrible to play ships than the Leone class Destroyer (Looks at the Ciclone class Torpedo Boat for a close in BR Italian ship), one possible buff is they could be rated as a cruiser as they started life as scout cruisers before being re-rated as destroyers.
Or they could probably go down to 4.0 as they were originally added at 4.7 & at 4.0 there’s some better ships in the Italian tree & across other national trees.
On a sidenote, you could unmod the torpedoes, sure they’re short range at 4000 metres but man the speed increase is mean at iirc 41kts.
Idk I actuallly like Leone and Tigre more than any Soldati class destroyer. It feels a bit more survivable, while HE shells can do some damage, but you should get used to ballistics. Torpedoes are meaningless since I play naval RB. AA is questionable, I prefer 40 mm over multiple 20 mm Bredas which are useless most of time, also Tigre has 76 mm secondaries, which is nice.
Maybe it can get br decrease, especially if you compare it to postwar Impetuouso and Geniere from the same TT, as well as entire Soldati class, but not to 3.3 obviously.
PS and yeah the worst ship in the game is Cyclone class RN Ghibli from the Coastal TT of Italy. That thing is downgrated in every single way reserve destroyer, but for whatever reason placed at 4.0.