What the stats don't necessarily illustrate is the relative difficulty of the kicks.
This could be total rubbish, but my perception is that Simmonds typically has easier kicks.
Here's my logic
The majority of the tries Exeter score are close range efforts from lineout drives or pick and go. This tends to mean that a lot of the conversions are taken from closer to the middle of the field.
Quins have no trend to the way we score - we take what we can get so a lot of the kicks can be quite difficult from wide angles.
In any case, I'm with ragerancher. It doesn't matter who is the slightly better kicker ... both are too good to be ignored.
*Old Hooker basically made the same point while I was writing my post ...