[@Turboshitter]Shadow says that archer hasn't actually been summoned yet if not then I'm retconning it in that he hasn't so Indra can have archer/assassin whoever. I'd prefer he be assassin's master but if shadow wants to be the master of assassin instead then that's all good.

As for Lancer's summoning he's going to be gutted by assassin and the holy grail's going to mulligan it not unlike it did for Kotomine kirei and the church is going to allow a re-summoning on this occasion since it's early and lancer shouldn't be taken out at the very first day of the war.