Hmmm. Sensui should be fast enough to pick Team Fate off, individually or as a group. The only means that the team would have to dispatch Sensui would be via Gae Bolg or Ea. But I highly doubt Gil's gonna have the time to prep them from Gate of Babylon and Sensui should be fast enough to easily evade GoB spammage.
Ionian Hetairoi can be taken out with the Sacred Energy Beam, which destroyed hundreds of demons in an instant.
After all he beat 3 A+ class fighters with no difficulty, even taking an island+ level attack to the shoulder without a scratch.
I see him winning scenario 2 with mid diff at max