I do like the suggestion that a modernised version of the yeoman should be a mixture of a naval yeoman and an army batman, so in addition to admin, they would accompany their boss on diplomatic missions as a personal pilot or bodyguard.
A batman was the army version of a maid or valet. Nothing to do with security or anything else. It was a side job, in addition to a soldier's normal duties, and was paid from the officer's own funds.
I only like it from a story perspective becauseit adds greater depth than please sign this.
I don't think "Here are your best polished boots" would be any better.