Off the top of my head, I can't imagine anyone who would be more dangerous as an Archer than Gilgamesh or Iskander as Rider, with the exception of MAYBE Yi the Archer. Can anyone think of any other legendary heroes with a similar or greater potential level of threat when summoned as a Servant? I personally think Sun Wukong/Son Goku summoned as Lancer would make for a pretty interesting matchup for Gil. Even though true Divine Spirits can't be summoned, how would a mortal monkey who grew powerful enough to rampage through the heavens and make the gods themselves cower in fear stack up against servants like Gil or Heracles as a Lancer?