Since all Six Samurais can have a different Six Samurai take their place when destroyed, you can use this to summon a powerful Samurai and then destroy a weak one at the end of the turn.
Bring back one of your Six Samurais and attack a monster on your opponents side of the field with the same ATK as your Six Samurai to destroy them both. Since your Six Samurai would have been destroyed at the end of the turn it doesn't matter if your Six Samurai is destroyed as well.
Gladiator's Assault adds a new card to the mix, Spirit of the Six Samurai. You can equip this Union Monster to the Six Samurai that you bring back to give it a 500-ATK boost, and then at the end of your turn, the Spirit will be destroyed instead of the Six Samurai. Even better, since Spirit is a "Six Samurai" monster itself, you can use Return of the Six Samurai to bring IT back, equip it to a Six Samurai, and then lose nothing.
You can also use Cunning of the Six Samurai to switch the Six Samurai you special summoned from the graveyard. As a result, it will not be destroyed, because it is treated as special summon from Cunning Of the Six Samurai.