I recall about a 100' Rohn 25G communications tower that was on a postage-stamp lot, and the guys were probably anchored at less than 50% of the tower height. They had a lot more guys than usual, as I remember, maybe a set every 15 or 20 feet. That tower stayed up for decades until it was dismantled when the business shut down.
I used a lot of overkill on mine, particularly at the guy anchors. It took only a few dollars worth of additional concrete to increase the size of the anchors from what was recommended for this region to something extra HD even for coastal areas.
After the anchors were poured, the concrete guy had some left over. He asked me where I wanted him to dump it. He said they would not take it back for disposal. I knew that a pile of concrete would harden into a boulder that would be a PITA for decades to come and very expensive to remove, so I told him to top off the holes where he had already poured the anchors, which were supposed to have been buried a couple of feet below grade. He had enough concrete left over to fill each hole to within 6" of grade. That way, I didn't have to worry about disposing of the extra (they must have miscalculated and made up more concrete than I had ordered), and it made each anchor ever more overkill.
I feel sorry for someone in the late 21st century who might have to remove those concrete anchors and the base pier, which I also made substantially heavier duty than recommended.
