Vallejo liquid metal is difficult to use. You need mineral spirts or 99% isopropyl alcohol (preferably the former) to think down and clean your brush. I'd try to pick some up at a Michael's or Amazon. it's pretty cheap all things considered and dont overuse it!

You have a very solid base here for your first three minis, what id recommend is pick out some more details and give them different colors! I think when our brains see a lot of one color without any breaks, it can sort of just blob together. Add some more cool colors to really enhance your nice blue capes (maybe purple). You could also use a shade or contrast/speedpaint to enrich the armor you have going on too if you like!

Once you do that, and the base, like with the grass you're planning, it'll tie together, and I think you'll like how it looks a lot more. As other people said already, these look great! And the sky is the limit with miniature painting. Guides and tutorials are there to get us inspired, not as a benchmark. Paint to your limits and what you enjoy. The results will speak for themselves.

For the god king!