Moisture filters before the pump, on the intake side and at atmospheric pressure, usually do little to pull moisture out of the air. That's why the hand pumps often pump moisture into your gun. The filters on them are only a sales gimmick.
Pressurized air is much easier to pull moisture out of. Some desiccants werq very well at pulling moisture out of pressurized air and do it quickly. Different desiccants werq at different temperatures that's why it is good to have both a high and a low temperature desiccant in your filter.
I have my set up like this and replaced the valve on my Ninja tank after two years of filling and the tank was completely dry inside. There has never been any water at all in any of my tanks, guns or in the final output my system and I have been using it for three years.
There is always water released when I purge the compressor, every five minutes while it is running, and in my small YH filter on the bottom of my desiccant filter. The desiccant filter has been in use nearly a year now. It has been taking on water, all of that time, and will need replaced again shortly. The filter on top of the desiccant filter is still dry though as is the air going into my tanks and guns.
I just finished tearing my Impact down after three years of use, and fills from both the compressor and tanks, it has no signs of moisture intrusion either.
