I also think that these are a bit soft.
I don't know if this will help, but this is my personal experience with AF...
My experience:
A lot of my shots come out a bit soft. I used to set the AF mode to "One Shot", compose by focusing on my subjects eyes, holding my shutter button halfway to lock my focus and then recomposing to the desired scene and pressing the shutter the rest of the way.
But I offten got this "soft" effect, or the wrong part of the picture in focus. For example:
Eva. I focused on her eyes... But when I recomposed the focal plane ended up on the dolls face...
Now, I use the AI-Servo mode of my Canon... (not sure what Nikon and others call it).
This (in most cases) maintains my focus lock even when I recompose the image (as long as I keep the shutter down halfway while recomposing).
I think it's also important to point out that I set my camera to use only one AF point.
Relevant notes:
"One Shot" is a setting that Canon uses within their AF Mode system
AND their Drive Mode system. If the difference beteen the two is not clear to you, look in your camera's manual.
This method may not work well with static targets... As the AI-Servo may get "confused".