They're not bad character designs, in that I can get at least a general idea for the age and personalities and stuff of the characters.
The main feedback I'd give is to use this as a starting point, and to push yourself in terms of "specific".
So as an example, the guy in the top left is wearing a parka, boots and what appear to be... flares? And from your commentary, it seems like you made notes yourself saying you want the parka to be more distinctive and gritty, so I think you have a feeling that this design isn't quite getting across all the information you want it to. So as a next step, I'd recommend doing some research and looking at parka jackets. I reckon if you threw some pockets on there, like an old army surplus parka, maybe had it halfway fastened instead of neatly zipped all the way to the top, so it looks messier, you'd get the gritty vibe you're aiming for. Then I'd maybe pay some attention to the specific shape of the pants and boots. Are they meant to be flares? Or wideleg/carpenter jeans? And then the boots... What sort of boots are they? Like workman's boots? Army boots? Look at some reference and see if you can be a bit more specific with the garments.
Specific choices in exactly what your character wears, and how they wear it, even if you draw it in a simplified way and just evoke the shape, are what makes a character design really sparkle.
