[quote=@Cu Chulainn]
[@Turboshitter]
Quick question revolving around how we're starting. Would some of us have some time to be summoned earlier, like how in Apocrypha, Darnic summons Vlad months in advance so he could set up (since otherwise his NP wouldn't work)?
[/quote]

That is indeed the case. While I imagine not all Servants would have been summoned ahead of time, Caster and Lancer would more than likely have been around for a while by the start of the war.