Adam Golberg analyzes success rates for various disciplines applying for grants from the UK’s Economic and Social Research Council (ESRC):
ESRC success rates by discipline: what on earth is going on? | Impact of Social Sciences.
Not surprisingly, some disciplines fare better than others. The question is why. As Golberg asks, are some disciplines ‘more back-stabby’ while some are more ‘back-scratchy’?
The only way to answer this question would be to look to see the disciplines of the people who served as reviewers for the specific proposals. Although ESRC publishes a complete list of the members of its Peer Review College, it is doubtful they’d be willing to share which reviewers on the list reviewed which proposals. If ESRC wants to know the answer to Golberg’s question, though, they will need to look into this question.