Cup cake mix!

Hi Lindsey, I have to make 60 iced cupcakes for a birthday party and was going to use a classic Victoria sponge recipe but I notice that Delia's recipe for cupcakes uses less butter and sugar rather than equal amounts normally used in a Victoria sponge recipe. Is this because these are better proportions for cupcakes?
I enjoy the website very much.
Thanks and I hope this doesn't sound a silly question .... I am a bit nervous about getting it right having been asked to do them for a friend!
Kind regards,
Su Mutch