Excellent results, and you have a good eye. I especially appreciate #2, the bright plant with a dark background.
I find the Epson auto exposure is set to clip highlights a bit - this probably because in a typical snapshot with sky doing so results in a better exposure of the land bits and a perceived openness to shade. Sometimes with shots like yours I find moving the high slider further right helps - though then usually I need to slide it back in photoshop
In the case of your excellent scans, however, perhaps you'd only retrieve a slight bit of highlight on the last photo.