A comment from Emilio Bruna last weeks's post encapsulates a mentality that is common in review recipients, manuscript or proposal.
I actually think a much bigger reason a (pre)proposal might not make it through in one year or panel when it would in a different one is the luck of the draw wrt the three people reviewing it. No one who is an expert in your subdiscipline? Trouble.
Anyone who has ever served in the role of presiding over the review process will recognize this sentiment well. Having had to bite my tongue as authors complained about non-specialist reviewers when I had sent their manuscript out to one or more of their suggested reviewers, I can only imagine the calls POs receive.
But here's the question: Why are you writing a proposal for people in your subdiscipline? This is doubly pertinent at the preproposal stage, where only panel members read the proposals. As a panelist I have often read proposals outside my wheelhouse, but some of those have been among mine and the panel's highest rated proposals. Why? Because if you're writing for you subdiscipline, you're doing it wrong.