In the game, the turret protection of Leopard 2ri and Leopard 2pl is exactly the same, but since Leopard 2ri is modified from the later C-Armored Leopard 2A4 and Leopard 2pl is modified from the earlier B-Armored Leopard 2A4, the turret protection of Leopard 2ri should be better than that of Leopard 2pl.
If you have any information for that use this site to create a bug report
https://community.gaijin.net/issues/p/warthunder
I think someone posted a thing about how in game the L2A4 is some weird combination between the B and C amour variants, so the base L2A4 is sort of irrelevant until gaijin fixes that.