In Star Wars: Battlefront II, Mos Eisley (and other maps through Xbox live patch) has a mode called "Hero Assault", but it is not the same Assault you find on the other maps. Instead of a space battle, you will find yourself battling with the Heroes available from the game with the two sides heroes and villains. The game is scored like the regular Assault, but ends up playing like a Conquest, except for the inability to take over Command Posts. In this mode, heroes have the standard infantry health bar and can use a medical droid to heal them, although they do not recover health quickly at all. The mode can be slightly unfair because the Heroes can win easily, but the Villains will generally never win unless the player joins their team or switches sides.
When playing as the Heroes, you generally win anyway, but one of the best characters to play as is probably Aayla Secura. When playing as the Villains, one of the best characters to use is Darth Maul or Anakin Skywalker/Darth Vader. The Emperor, as well as Count Dooku, are not necessarily a good choice to use in this mode because they are quite slow and their attacks are not very effective against other Heroes/Villains. One of the only reasons for the player to use these two characters is to release Force lightning upon your enemies.
Heroes: Luke Skywalker, Chewbacca, Princess Leia, Han Solo, Mace Windu, Ki-Adi-Mundi, Aayla Secura, Obi-Wan Kenobi Villains: Darth Vader, Anakin Skywalker, General Grievous, The Emperor, Jango Fett, Boba Fett, Darth Maul, Count Dooku