Not possible. (because this setting simply gives an extra (y=1) army for x territories, as you can't own 1/2 of a territory it's not possible. What you want is a setting that adjusts the y-value, that however does not exist.
I do like the idea of a multiplier for this setting though.Maybe create a uservoice for it? http://warlight.uservoice.com/forums/77051-warlight-features
Edited 3/18/2015 21:54:14