I feel like we can make a few changes within this set.
First and foremost, I cannot agree to the current Header value. He simply does not have the same level of accuracy in his headers as Jagielka or Koscielny. Too often when he wins and aerial battle, he nods the ball on to an opposing player. This seems to be an inherent problem within the entire Arsenal back-line in all honesty, our defenders do not seem to logically consider where to head the ball. When it comes to aerial balls towards the box, they simply head it out to clear away rather than head to instigate a move. I do not know whether this is due to panic of the ball coming towards our box (Our back-line's mental state is shot to pieces and there seems to be disorder and a fear of conceding) or just a lack of thought, but it means that I cannot see our current back-line having overly high Header values - irrespective of how often they win their aerial duels. In this department, I'd reduce Sagna's Header value down to a 78.
I'm rather uncertain about his current Defence value. He's a full-back more than capable of channelling the opposing wide-man away from the action and into running the ball off of the pitch, and for this to happen in game, you have to enable a good Defence value. Similarly, his tackling is of a really good standard. He is able to contour his body well to win the ball. He is also very able at intercepting loose passes and although that is a big Response issue, it also requires being in the right position to win the ball.
However, is he really much better than Evra in this department? I would argue that he isn't. So should there be the current 6 point deficit between the two of them?
What is for certain is that his Aggression needs to be higher. Someone suggested that he needs the WB position, and although he doesn't play or need this position, the fact that he bombs forward with such regularity and to take up positions so far forward indicates that he can fool people into thinking that he's one. Again, I would draw a comparison to Patrice Evra in this area.
And by raising his Aggression higher, we will be able to see two traits:
1) Sagna will go forward much more when the team is in possession of the ball and will be a part of the attack more often than not
2) By giving him a high Aggression, it is also produces a scenario in which he can be caught too high up the pitch and thus out of position. As a result we will see the gaps that he infrequently (although it is rather rare) leaves (Case point, look at the 2nd goal of the Liverpool game on the weekend. Where was he?)
Another issue that needs to be raised is his Long Passing Accuracy. It may not be fun to say, but Sagna's crossing has definitely improved. More often than not, his crosses are weighted well and are not over-hit (the same cannot be said for Theo or Gibbs). I'm certainly not saying that he needs a drastic increase, but I think a 78 would be agreeable in this area.
I'm also under the impression that we can make some increases to Sagna's shooting stats. Although it was not often that he took a punt at goal, when he did it was surprisingly potent and accurate. He produced some cracking goals against Celtic and Everton last season (off the top of my head, think he may have scored another) that, for me at least, suggested that there shouldn't be quite this chasm between Sagna and Assou-Ekotto in this area.
I also feel like we can make some changes to his Balance, Tenacity and Team Work, if only by 1 point reductions. I feel the Balance is rather pertinent and I know that it has been the cause of much discussion. From his performances last season, I would not say that he had the level of hardiness and physical strength of, for example, Stephen Carr (who is currently very underrated on here in this department) or John Arne Riise. Again, I would put him at an Evra level in this department.