There are thousands of beneficial combinations available.
For a simple, "1-size-fits-all" solution, I say a
regional wildflower mixture would do most of what needs to be done.
Almost any Wildflower vendor on the internet offers 1 pound packs of regionally selected
native wildflowers for about $30. These are native to your region, and hence usually thrive with natural conditions. If it does not normally rain in your region during the growing season, then these plants
should do fine without watering - they grow wild there (with no intervention). These same wildflowers supply both food and habitat for the natural pollinators as well as other beneficial insects.
Most of these mixes are a combination of perennials, and annuals. With ZERO attention, the annuals will reseed themselves each autumn. So, these flowers should turn into a perpetual beauty spot on the map.
I would say that for 2 1/2 acres, 3 pounds of seeds would convert his entire
yard into a beautiful meadow that took care of itself while assisting the fruit/nut trees. That same 3 pounds would attract
enough pollinators to
increase fruit production through better pollination, and it is also helping to balance the natural insect populations, thus reducing disease vectors.
The beauty alone would make this a great companion. All of these other benefits are merely icing on the cake.