given that the GEFS has a pretty large progressive bias and that the -NAO is formed due to wave breaking, I would be more inclined to believe the EPS and GEPS
the trough also rolls over and slips under the block. it's not a true -PNA... and there is also a -EPO that provides Arctic air. really exciting look here
i think when you have a -NAO like that, you just need the -EPO, PNA can be neutral to slightly negative
a +PNA doesn't show up on the mean generally in those KU type patterns. it's just transient as the storms develop