Ponytug,
First, I'll tell you what I have and the critters we had aimed to keep out at the time of building. Our first issue was with the deer. We live on a lake surrounded by deep forests. We had 6 ft dia cages, 5 ft tall. The wire is welded 2 x 4 in openings. That reduced the browsing significantly. But a huge pain to prune and shape the trees. As you might know, peach trees are pruned to an open center, so trees are 7 ft tall by 15 ft wide. Peach trees grow so fast we had to ditch them spring of year 2.
We decided to go with the electric fence. I had read that the main issue with E-fences was keeping the grass away so not to reduce the zap. So I took those cages and cut them into 20 in strips. Those fence strips were run along the bottom of the posts and the E-wire every 6 inches above up to 5 ft. It was amazing, no more deer. In fact, we hardly saw them any where near the home. Then, the raccoons moved in, got tired of the trap and shoot method. This was off season of fruit but they were climbing our porch posts to get bird seed. I ran a second hot line under the entire length of my deck. From there each post top got a "halo" held out by 1/4 in fiberglass rods. The posts are steel luckily so already grounded. No more 'coons' on the deck or fruit trees.
What critters we have now and the mods I would make. Over the last two years after loosing our local 6 ft black snake, the darn chipmunks moved in. They can jump right through the 2 x 4 in wire fence. They take a pea sized bite out of the green fruit, sometimes pluck and drop. Either way, the fruit is mostly bad. Between mouse, rat traps and a combo of 4in sewer pipes/jack Russel terrier, we have reduced the problem. Killed maybe 10-15 this year.
After years of having squirrels happy to steal from the bird feeder and stay out of the orchard, they moved in. I have shot and trapped 10 in one week.
If I could turn back the clock, I would have used a smaller mesh to keep out small critters, chipmunks and squirrels. Forcing them to climb the fence. Then using a fiberglass rod to hold the first hot wire 1-1/2 in away from the fence wire top. Also, fence could be taller to reduce weed wacking.