That's actually a good point the folks above have been raising - the second round would have to have custom-built Servants provided by the GM. The problem with established Nasuverse protagonists (Shirou and, by connection, EMIYA) is that they are designed to take advantage of their bullshit super-specialised power at just the right moment, and are useless otherwise. Conversely, antagonists are supposed to be entirely bullshit except when countered by this super-specialized power. It makes for tense situations and good reading, but poor game balance.