I have a similiar setup for my parents with 12" pavers. Going on almost 8 years now. Citrus, mango, longan, lychee, guavas, wax jambu, persimmon, jujube, anonas. I thought after the pavers some of the plants really began to thrive especially the lychees and a mango on turpentine rootstock. The only plant that died during this time was a plum tree which may not have liked it but it was also an old tree 25+ years. I feel that the pavers acted as a natural mulch. There may also be some exhange of oxygen through the gaps between each one. The area is pretty much clay soil, the pavers seem to help a bit with drainage. It doesn't waterlog as long as before like in the past. Also when I lift a paver it was always moist with quite a bit of bugs thriving even in the middle of summer. Only downside is any dropped fruit would be heavily damaged ahah. Overall, I thought it was a success.