It could be that a combination of smaller rings means there will be less friction (fewer teeth) so perhaps less resistance (except that there might be a lot more friction between the links of the chain because the chain is wrapping around a smaller radius as you mentioned) but then, the smaller rings would result in a slower moving chain so maybe there would be less rotating mass to deal with, but... irrespective of what Old Seat of the Pants may believe, none of this has anything to do with a change in leverage since the length of the crank does not change and the fulcrum would still be the center of the bottom bracket.