Weren Wu Jen |
While you can take multiple Archetypes if none of them conflict with each other, you can still only take a specific CLASS more than once.
So no, your friend cannot be a (for instance) a Paladin (undead scourge) Level 3 and multiclass into Paladin (warrior of the holy light) Level 1.
He could, however, be a Paladin (undead scourge AND warrior of the holy light) Level 4.
Most Fighter archetypes replace the same things, so that usually isn't an option.