I like the arrangement and the spacing, love the pot and also enjoy the photography. I'm new, so take this with a grain of salt: the leftmost tree and the largest tree both have pretty prominent "Y" structures at the top, which I find a bit distracting.
Unlike Atom#28 I think the regular spacing looks more like a park than a forest. Spacing is one of the hardest things to get because it appears our human brains are wired for uniformity. I have to concentrate really hard to achieve to random placement when assembling forest bonsai. I assume you have just assembled this so it would still be OK to rearrange them a bit if you want to. I've often shifted trees or moved whole lumps of trees the following year after it became apparent some were just not quite right.
I do like the space you've left on one side of the pot. So many build the forest to fill the entire space or assemble it right in the middle. Asymmetric is better IMHO
I would prune the red lines and pick leaders. Then wire the leaders into shape. Prune high/heavy branches and the where the purple circles are you should have only one branch. Add some more trees when you can.
I disagree with the suggestions to add more trees. I think you have a very nice start. Good, irregular spacing of your trees. Park Like? Not really, this is a planting in its first season, in very few years it will become more dense. You have reasonably good variation in trunk diameters. Not bad at all.
The pruning suggestions from @Maloghurst are good. Eliminating one of the 2 heavy top branches is important. As the tops will tend to get heavy long before lower branches develop. In the future, balancing vigor to keep the trees in proportion will be critical.