I think this separation between what different recruiters want actually makes for an easy way for the applicant to filter out the companies whose culture doesn'

I think this separation between what different recruiters want actually makes for an easy way for the applicant to filter out the companies whose culture doesn't fit their own. Make your cover letter and resume fit you, if it gets dropped because it isn't what the recruiter wants (too short, too long, etc.) then that company probably wouldn't have been a good fit anyway.