IMO you will enjoy a smaller pond with the correct amount of water compared to a larger pond that is just a shallow mud hole for part of the year. The biggest exception would be if you have some source of supplemental water to top off your pond during dry spells.

It might help a little to "add" some more drainage area for your pond. Since you will have earthmoving equipment on site, you could build a small terrace to capture more of the surface water flows on your property.

(Discussion based on assumption that your pond.PNG is oriented due north.) The runoff from the NE corner of your property is going to go downhill the the west and then turn north and flow off your property past your pond. If you built a terrace along the 1451.5' contour with a berm at your north property line that went up the slope, then that extra water could be routed to your pond.

You might not need to dig the small "bay" at the SE corner of your pond. (Unless you want that bay for some other reason than capturing the surface runoff.)

Your terrace does not need to be at any specific contour, so you can fit it at any location that is pleasing to your eye. Right at the edge of your trees might look nice, but be careful not to route leaf debris into your small pond.

Finally, I think that the USDA handbook is an excellent resource. I believe their calculations for pond size versus watershed are based on average levels of water loss due to seepage AND evaporation. Your Soil Survey results indicate you probably have good clay. If your pond is built and sealed correctly, then you might have less than average water losses due to seepage. That might allow you to "cheat" to a slightly larger than calculated pond size, but I would not cheat too much.

If you spend less money on a smaller pond, that always stays full, then you might be able to do a small expansion later. If you build too big to start, then you have spent more money for a worse pond.

Good luck on your project!