This is a deeper dive on the stones and their locations. Please note that 317 stone tablets were built after the 2 tsunamis, 125 (40%) of them were washed away or destroyed by the 2011 tsunami. https://thefunambulist.net/magazine/cartography-power/incomp...
That suggests a possibly better strategy (though very long term): pepper the portion of the landscape believed to be safe with "it is safe to build here" monoliths, each as stable as a typical building, and over time only the ones that speak truly will remain.
Sadly, that's at least partially true. But rebuilding on a sight where a home was destroyed eliminates the information value (that this site isn't safe from tsunami) and the coverage is far from uniform/regular (so you can't tell if there are no buildings in an area because it was previously undeveloped or is unsafe).
Japan has a bad habit of considering buildings as disposable. Odd that a land with 1000 year old temples knocks down 40 year old houses with zero remorse, but that seems to be the case.
I'm not sure that judgement of calling it 'bad' is warranted. Certainly it's different that western approaches to housing but I'm not sure whether it's better or worse. My understanding of the 1000 year old temples is that they are periodically replaced and rebuilt, like a Ship of Theseus situation
There are lots of old houses in use and for sale in Japan, but many people prefer building a new house to renovating or maintaining an old one - partly for practical reasons, partly because newer structures are more likely to be earthquake-resilient, partly due to haunting.
It should also include the location of where the stone lived before the tsunami. That would help future archaeologists determine how big the tsunami was