@embla I like the background foliage of the two on the left side, (it looks very dense in the two on the right) but if it's supposed to be a flat, open landscape, you might want to change it so it looks more grassy instead. This looks like there are plenty of trees and shrubs, so if that's ok--it looks good.
I like the smaller rock in the middle of the water (in the lower left version). (In the other ones, I think it's a little distracting.)
For colors, I like the two on the left, and I think the upper left is my favorite. I like the light blues of the one on the upper left.
But if you are going for sunset, I like the one on the lower right--I'd just change the sky color a bit. I would start on the right side of the sky with the yellow in your palette, then moving to the left, add a little of the reddish/orange. Then have that fade to a lighter blue--like the light part on the tip of the blue at the bottom of your palette and give it a gradual fade from the light blue to darker blue (using the same blue paint color), so the darker blue is on the left side of the sky.
At sunset, if you have your back to the sun, you see a darker blue sky and if you look toward the sun, you see the sunset colors (often reds, pinks, &/or oranges) with light blue sky. (I've seen sunsets with a lot of pinks and purples, too--especially if there are a lot of clouds. So you can be very imaginative with it. But since you already have a pallet that's working, I'd stick with that.)
I like how the figure on the left (in the lower right version) has some color to the clothing on the side facing the sun. Maybe you could add that to the other figures as well.
Nice composition and a fun, peaceful image.