Hurri D certainly is not 'less accurate'
aim right and it will go just where you aim it. consider gravity, lead and the position of your guns (if you are a litle leaned the shots will go differently then if you have both wingtips at same altitude) It won't just go random, it IS accurate as the IL-2, but the IL-2 'feels' more accurate due to its ROF
The way you use those planes are also different. at least the way I use them differ to much and I still see many people augerin' on them because they think it's the same thing.
OK, perhaps the weapons are just as accurate. But I maintain that the IID is just a less stable firing platform, especially for sustained fire. The ROF itself has nothing to do with the percieved accuracy.
The biggest issue is how the IID's verticle stabalizers just aren't upto the task of handling recoil from the 40mm's. Now maybe the IL-2's guns just have less recoil, maybe the verticle stab is bigger, maybe all that weight in armor has something to do with it. But the IL-2 is a much more stable platform for sustained fire.
I also maintain that, excluding travle time to the fighting, the IL-2 is more effective at quickly dispatching vehicles. And that matters, and matters a LOT in many circumstances.
You don't tend to need things dead, and dead fast, unless things are getting out of controll and you're getting swarmed. If things are perfectly fine, and you've got the situation handled, then you generally have time to up a Panther or Tiger II and go on a rampage, or wait for ordnance to pop.
Another reason the Stuka will be preferable to the IL-2 and IID in many instances is that the bomber hangers are often the last structures to be targeted by attackers, which means that the Stuka will be one of the most effective anti-GV aircraft available when things are getting down to the wire.