About this acacia I found this in English,
https://fairdinkumseeds.com/products-page/ethnobotanical-or-medicinal-plants/acacia-farnesiana-vachellia-perfume-wattle-seeds It lists some of the most common 50 names of it, but I've found a translation from Greek into musk-tree.
In Greece they call it Ghaz'ia (Γαζία) and they consider it very different from other acacia. They seem to all have been transplanted species from Australia where long ago built their defense on surviving great fires. I curse these trees every time I try to do something close or under it. They make a rose bush feel like french lettuce
The bean (seed) sacks eventually dry on the tree and fall while they are hard. When it rains they stain everything around them in black purple (natural die for all your clothing needs).. If you throw them into compost eventually new little ones will come out and become long skiny and indestructible very fast. Because its wood is fairly hard, even skinny branches provide other crawling plants and birds a solid base to climb on. Even cats walk on its skinny branches with security. [You can make fine drum sticks of long straight branches]. So melons, pumpkins, etc will do great underneath and even if you don't eat them or get significant produce, the dried up plants in the fall create a grade shade/cover for the living soil underneath. Just rip them off the acacia and drop them below. Cheap soil cover.
With a low peak and high altitude I doubt there is any significant underground water, but if you see any old Eucalyptus in the area that is where it is at. I believe acacia is also a good indicator of underground running water. I am not suggesting you dig a well but what sometimes looks like a dry arid dead land may be the surface of a big creek. I would concentrate all early efforts in building soil at the highest spots of the land. Learn olive-tree trimming by selecting the oldest branches to cut and leaving the newest each year. The best olives come from branches that are 1-2years old, while the old branches don't produce well. This makes the tree healthier and more resistant to pests. Instead traditional practice is to let it grow big for a few years and then cut it all above 1,5m and leave a pole for 1-2 years without any production. The other way has good production every year. Keep all the fine trimmings on the ground below and around the tree. Don't listen to those old fools as they have been generationally fooled by the expert fools of industrial agriculture. The same people that sold them pesticides to spray ON EVERY SINGLE OLIVE 3 times a year, every year taught them how to care and trim olive-trees. I use sunflower seed oil for stir-frying.
Make things grow underneath them with mulching the finest pieces. Olive tree wood is the world's greatest wood stove fuel, it make the whole valley smell nice. The clay soil and dry sunny conditions you describe for the summer make it an excellent source of building (example outdoor wood stove) things.
You can also use those branches in making water traps higher up. Because it is so oily it doesn't rot very easy, so if you stack them well in line and slow down water and keep adding mulch you may get a green explosion.
Plant wild flowers from the are and anything that would attract bees. Learn some basic bee keeping and get a few boxes. Get some shaded piles of mulch and broken branches, keep it moist, fungi will grow, bees will come and eat from there when there is no flower honey, so they will stay. If you get them to stay year around then it is your Green Light, the forest creation is on. You can just sit and watch it grow.
What's the distance from the closest ocean/med body of water. If there steady air currents from that direction and you have peaks on the ground in places that are well venter think of making some kind of geothermic moisture trap. Basically you need to stick the longest heaviest metal pole in the ground in a sady cool place (pipes used from old water drilling work well) insulate the part near the surface and above to the place where you'd weld some high surface metal that would also drip condensation into a tank. You then either allow overflow to run into a channel or let it just run into mulched covered soil. Solar-heated Amonia refrigeration cycles may be an expensive solution, or wind-powered air compressors made into refrigeration cycles. Even compressing air may work in high wind areas in condensing ocean/atmospheric moisture.
If you have so many available working hands why not offer them with a truck in cleaning other peoples olive groves and gardens, as the fools think the soil needs to be seen by sunlight and be free from "weeds" to produce oil. Bring all this organic material into your landfill
Later do a seminar of the gold they paid you to take away from their land into yours when you will be producing double the oil than they are producing while the pest (dakus) that destroys olives will be staying away.
Keep olive trees low and use the shade to grow taller trees between them. Learn everything you can about any small weed or bush or flower you see on or around the area. Take hikes higher up and collect samples and seeds. Nearly every wild specie you find in such climatic conditions contains exponentially more nutrients and therapeutic substances compared to what you find in wet climates. If you see any dense vegetation and trees out in the wild, close to the peaks of the hills around you, use the method of dipping little sacks of sweetened wet rice about 15-20cm below the surface and near the root of each healthy tree. come back 40 days later and take it out with some of the surrounding soil, take it back, put it in big buckets of chlorine/fluoride free water (rain water is best) with some molasses, stir up, keep in a cool shade for an other 40 days. Take out and mix 10:1 with more rain/well water and put it in the roots of any small tree you are growing. The best forest acceleration method I have discovered. If you spent a fortune buying the best mycorryzal culture from the other side of the planet not only it may never work, it may even be hurting things. You want to spread native old growth and species, plant and living matter, and displace the newcomers (humans acacia palm trees etc.).
Peace, by any means necessary