You could bring in Mozart. He's the only other Servant who uses the same voice actor as Gil.
I'd consider moving him up in your priority queue personally - to be useable for farming at least - as he's an event Servant for the Summer rerun in a few months. Which, all told, is a rather long event with relatively few event Servants available, especially for F2P players. In this case, you'll want to have event bonus Servants in the party for every conceivable mission as they decrease the grind for the three concurrent point ladders by a notable amount.