I would understand it if the metallic activity series
Li, Cs, Rb, ... Pt, Au corresponded to electronegativity or ionization energy. However, the way it is written, lithium will displace caesium, while caesium will displace rubidium (it goes from the top of family 1 to the bottom and then up again).
This order seems so random. Is there any order to it or is it just determined experimentally through trial and error? In addition, wouldn't different valences on the metals affect their placement in the series?