Earlier quoted context omitted.
Writing a grant proposal is about as hard as writing a paper. So if they apply for three grants and also write three papers in a year, then yeah - that's 50%.
Getting a grant proposal accepted is much more difficult than getting a paper accepted.
I don't think that's a valid generalization. It depends enormously on the funding agency and the place you're submitting the paper, respectively.
You're not going to be able to do a good grant proposal unless you have a good track record of research, with multiple papers. So in that sense, a grant proposal supersedes a single paper.
But, given that you've already done all those papers, a grant proposal is just writing, not new research, so it should actually be massively less work than doing all the original research that goes into a paper.