I haven't shot professionally for almost a decade, but if you are willing to listen, I have a few comments:
Images 1 and 3 have one thing in common ... a 1/1 lighting ratio. The problem with this is that a ratio that close causes a "flat" look to the images. In most portrait circles, the ratio is around 3/1. That means that if the fill flash (the one over your shoulder) is at f/5.6, the main or modeling light should be at f/11 when metered seperately. The correct setting for this setup will be f/11.5 ... try that ratio the next time... and I think that you will have something with more "snap" to work with. I like the image number 2, AND it's a direct contrast to the other two images showing a lighting ratio of around 5/1. As you can see,,, the other end of the spectrum isn't a bulls-eye either (loss of detail in the shadows).. But I'll take too high a ratio over too low of one any day. Here's something I shot last week:
Hope I've added something constructive.