I just did an h5 analysis of that Euro run and the intricate interplay between multiple pieces of energy(vorticity) that allows the one that induces 'our' storm to sharpen and dig that far southward and it is pretty insane how it worked out. What would really help get a NS vort to track underneath is a sharper/more amped PNA ridge, but its being kept a bit 'flat' by the positively tilted WPO ridge and downstream trough.