The heavy handed solution is to block by IP address ranges.
For instance 216.73.216.0/22 is anthropic.
They're very aggressive, this is the count of times they're in todays access.log
8436 216.73.216.62
They've got a couple of IP address they use so off with the whole ASN.
The problem is there's a bunch of free apps or vpns that get money by using residential IPs as proxies so you can also get vast numbers of requests spread all over a vietnam telco, like
14.176.135.196 is in the range 14.160.0.0/11 VNPT-VN
and was behaving suspiciously.