That's exactly what Rob does with VA's -- applies a relatively small cost to save him a ton of time, much more so than alternatives like trying to automate it with code.
I didn't say that the use of the term was illegitimate, part of the reason why "leverage" is so pervasively abused is because it can be legitimately used (or leveraged) so abundantly.
Much like "really" the term "leverage" is almost never needed and abused far more often than used appropriately. Yes, you can really use "really" really very legitimately really often, but that doesn't mean you should, really. The same applies to "leverage" which has been leveraged far past the point of reasonableness into the realm of abuse.
Personally I think the term "leverage" is best reserved for situations where something is put to use in an unusual or especially advantageous way. Making use of an assistant to take care of mundane chores so that you can concentrate on more pressing matters is hardly novel (not within the last few millenia at least), though it is still quite sound advice.