[quote=@Lonewolf685]
I don't suppose everyone would agree to meet at a prepared café before they summon their servants, leave behind all weapons, and sit at the table with the blinking red lights under the seats :3 It would make Tama's quest for love so much easier, neh?
[/quote]

Not really. 

The Lesser Grail won't descend unless the Servants are summoned and then die.

If the Masters die prematurely then some other magus with a Mark of the Chosen will summon instead.