How Can I Copy files to a Mounted Drive using AppleScript?
Finder

tell application "Finder"
    duplicate items of home to disk "WD" with exact copy
end tell


with exact copy preserves owner and group, like Paste Exactly.

cp

do shell script "cp -a ~/ /Volumes/WD"


cp -a is equivalent to cp -Rp. -p preserves times, mode, owner and group, extended attributes, ACLs, file flags, and resource forks.

rsync

do shell script "rsync -aE ~/ /Volumes/WD"


-E preserves extended attributes, ACLs, file flags, and resource forks.