Whike it was still only two games, I think there was a lot more guile in the play between Rafa and Herrera than we see from Valencia.
Valencia is very simple in his link up play in that it consists of one twos or passes down the line.
I'll try and find Herrera's highlights from the QPR and WHU games as you'll see what I mean.
The difference between the two is that Herrera is not afraid to commit to a run that will take himself out of position and even out of the play whereas Valencia's is much more conservative and measured. He's probably more calculated and plays the percentages well which is probably what Pogue is referring to when he notes his intelligence. The fact is that it's almost impossible to think of a time where Valencia has left his fullback exposed. When Rafael plays with Valencia it's Rafael that is more often then not on the overlap exploiting space whereas in the games with Herrera, it was Herrera who was happy to make the run wide from a more central position (as he's a RCM not a RW) and carry a player or two with him and in turn open the inside channel up for Rafael.
On the flip side, Herrera was also happy to start from a wider position and then play the one two with Rafael before carrying the ball centrally right across the area.
But again I'm comparing Herrera the RCM with Valencia the RWB/RW which isn't what we are currently talking about.
It's all a bit apples and oranges because we're comparing players with different team-mates, as well as playing in different formations.
If you're playing as a full-back ahead of a conventional winger the play will end up a bit more stretched and there's more spaces to run into. Plus you're much more likely to have a man advantage at any moment.
As a wing back, in a 352 you are much less likely to have a man advantage. There's more one v ones (e.g. vs Joe Allen) but less opportunity to over-lap and be slipped clean through by a midfielder.
Rafael's never (I think?) played as wing-back so we don't know how well he'd cope in the same scenario. Valencia has played as a full-back in a back four in previous seasons but wasn't very good at all. Although it was a completely unfamiliar position at the time.
So yeah, the comparison is pointless. Valencia is clearly a very intelligent footballer, though. The type of player Rafael would enjoy playing ahead of, particularly because he has the freedom to maraud forwards in the knowledge that Valencia has got his back. That's why they have always looked like a decent partnership, even when Valencia forgot how to be a winger and all the quality attacking play down our right came from Rafael.
Where we really looked awful, in the last couple of seasons, was when Valencia was playing ahead of Jones or Smalling. That just did not work, on any level.