Ah the questions are endless it seems... and I read the Yeast book!
Anyway, if I make a 1.5 liter starter wort and pitch a smack pack into it, will it result in a higher yeast count than if I make a 1 liter starter wort and pitch the same smack pack into it?
Yes it will. If you're not using a pitching rate/starter size calculator like the one on Mr Malty, YeastCalc, or Brewer's Friend, I highly recommend it - especially if you're brewing a lager.
I'm not sure what you're planning for the batch size/gravity of the lager you're brewing, but for a 5-gallon batch of an average gravity lager you're probably looking at a starter size in the 2-3 liter range to get up to the pitching rates you want.
See?! Another question! But first, yes I am using the calculator in Beersmith. When one references a '2-3 liter starter', I assume it means the whole starter not 2-3 liters of yeast cake after one decants the starter beer off the top, right?