As the saying goes: How long is a piece of string?How many ships/subs and types needed to protect our LHD?
It all depends on the level of protection we want to give to this ship.
You would need at least a TD2000, an I class frigate, a Milgem corvette, a Reis class sub. Ideally two of each.
But then again it can be fitted with self defensive weapons like the Japanese Destroyers/LHDs . But would still need escorts to provide protection.