Hello Andreas,
the saphostagent archive SAPHOSTAGENT197_197-20005735.SAR
for Windows on x64 64bit, release 7.20 and patch 197 looks good, saphostexec.exe is available in this archive. And if I look at the size for the saphostagent archive, then with each new patch the size is a little bit bigger, so I would say some information is added to each archive with a new patch and not removed. Please try to download it again, probably something went wrong during download, and please use the latest sapcar to extract it.
Regards,
Alwina