Companion plants are very different in Nth/Sth hemispheres and many combinations are even more local.
Gertrud Francke - Companion Planting has some good combinations, a good alternative (cover-crop gardening) and comes highly recommended by Geoff Lawton.
Examine your lifestyle, multiply it by 7.7 billion other ego-monkeys with similar desires and query whether that global impact is conscionable.
Give a man a gun and he'll rob a bank. Give a man a bank and he'll rob everyone. Even tiny ads:
Your suggestions have been mashed into the PIE page - wuddyathink?