Amanda, not sure what you mean by "swales", but if you put trenches going up and down a hill there is the issue of erosion. We get the occasional few downpours during the winter that can really do some damage when the surface
water gets running.
North facing is not so much about temperatures as it is about direct sunlight. Once your trees mature and get taller they will be more in the sun? Unless you have some really giant trees on the edges creating shade? Plus in the summer the sun will be high in the sky and will probably give your north side
enough sunshine.
Not sure how many fruit trees you want to plant, but try putting some reflective surfaces under them in the spring to bounce the light back up at the trees. A silver lining on a tarp, or clear plastic corrugated patio panels reflect amazing amounts of light (not the colored or opaque off-white ones) and you could use them later for something after the trees get taller. Those foil covered heat blockers that go inside cars against the windshield reflect a ton of light. Paint some boards or pieces of plywood with glossy white paint. Glass might be too risky to put out in an orchard, but there are plenty of reflective surfaces.
Fruit trees actually need a good number of chill hours during the winter to produce fruit, so don't try to warm it up in the late fall and winter. Be sure to match up your winter chill hour total with the fruit tree that only needs that much. We get maybe 400 hours of chill, where I am, and any fruit tree that needs 400-700 chill hours won't produce fruit for me (which is a lot of the heirloom types.) And about pollination, there
should be a list for which other types of trees will pollinate the one you want. Two of the same tree won't pollinate each other. But the pollinator needs to blossom at the exact same time, or there won't be any fruit.
An important distinction: Permaculture is not the same kind of gardening as organic gardening.
Mediterranean climate hugel trenches, fabuluous clay soil high in nutrients, self-watering containers with hugel layers, keyhole composting with low hugel raised beds, thick Back to Eden Wood chips mulch (distinguished from Bark chips), using as many native plants as possible....all drought tolerant.