Suggest Cesar Santos and Andrew Tischler for excellent examples of artists that bring portraits to a high level of finish. Both have hours of free videos on YouTube and excellent extensive video workshops available for sale which you can watch over and over.

I think they are good sketches . You may have answered your question, if you put a couple of hours into alla prima studies you can only expect a certain level of finish and detail. I suggest you try indirect painting. Try a charcoal drawing to get the proportions the way you want, work with line, planes and rhythms, avoid values. Transfer the drawing to your painting surface. Then do a wash with a fast drying color like umber, one color wiping out the lights with a cloth. Let that dry, then do a grisaille , monochrome painting, go one step lighter overall than your reference. Get all the values and shapes just the way you want. Once the grisaille is done you can leave it or add color with glazes and scumble on some lights adding a bit of impasto in the lights for emphasis. This is a slow process and you have time to evaluate at each stage. Bring each stage to its own level of finish.

First of all, I'd argue these *do* look finished. I think there are a lot of hard edges, sure, but that lends the painting a style. Artists like JC Leyendecker, John Singer Sargent, and Norman Rockwell have used a style like this to great effect. If you want more refined soft edges, I'd recommend blending with a brush with soft edges and slight texture until you're happy with the results. Start from big shapes, down to medium shapes, down to small shapes, down to the little things You clearly understand light and shadow in all of these pieces, though I think you may need to practice some construction. Overall, I think that you're better at this than you think you are. All you have to do is paint more. (I recommend Ahmed Aldoori's 100 Head Challenge for painting heads specifically.)