/usr/share/man/man8/arptables-compat.8.gz is in iptables-nftables-compat 1.6.1-2ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man8/xtables-compat.8.gz
/usr/share/man/man8/xtables-compat.8.gz