I haven't followed your other threads.
But if you have a table flat piece of property and drainage issues, you may have to look into other ways to convey surface water that are not based primarily on surface grading.
For example, my property (smaller than yours) is quite flat. I've got sufficient grading around my buildings to allow water to flow away, but the remainder of the property can become wet/saturated on the surface. I don't like this. In my situation, the soil stratigraphy consists of a relatively impermeable layer of slits, underlain by permeable river gravel (at about 3-4' depth below the ground surface).
I have created a number of "infiltration wells" or "dry wells" throughout my property to allow surface water to drain into the river gravel below and flow away. These basically involved me digging pits down to the lower gravel layer, at strategic locations, lining with geo textile and then backfilling with drain rock. I even connected a few together with "french drains" to add capacity and capture some of the surface water between the wells. It has drastically improved the surface soil conditions and didn't require me to bring in huge quantities of fill material to try and regrade the entire property.
Look into "dry wells" and see if they could work for you. As a bonus, they may not require any permitting or formal plans if you install them yourself since they aren't affecting the surrounding properties or other infrastructure (roads, ditches, etc).