Yeah, those stats are... baffling. He's Assassin, what is he doing with that sort of Strength? What good is it going to do him? O_o
Projectile--Daggers: specifying an exact stat is a bad idea. Especially those two. If a Servant doesn't have one of those... you are apparently taking on either someone extremely anaemic, or Caster.
Luck is actually somewhat understandable, as Assassin and Caster actually have high base Luck (B-Ranked).
... but that NP is outright insane. Every non-magus, non-Servant in the entire city gets converted to have Servant stats, Assassin abilities, and Servant skills? If this city has a population in the thousands, you have a B-Rank NP that can fight Iskander's army with almost no prana expenditure on Assassin's part. He turns one person, that turns two more, then they turn four, eight, sixteen, thirty-two... and that's if they only did two before stopping. No. No way.
(If each person turns ~four, then by the fifth iteration, that's already a thousand sleeper agents. It only takes 12 to turn the entire population of Tokyo into it--and that is the most populous city in the world)