As the GameCube version of the original came out after the PS2 version, it meant that Legends of Wrestling II came out a mere six months after the first. While yearly sports games have the excuse of people wanting the latest rosters, this is just a case of Acclaim getting a few more names on board, the big one being Andre the Giant.
The biggest change is that the HUD is a bit clearer so you can tell how the game works a bit better. Moves and counters are quick time events, so a target will move across your health bar and you need to press a button at the right time. Which is a pretty awful system that requires constantly looking between the events on-screen and your HUD. Everything else is the same, with the character creation still only having one face.