GNU tar - update tar file, overwriting the original file in command line(which is possible by drag-and-drop in Archive Manager)
Solution 1:
you could create a script that would create another tarball instead of updating the original and then remove the original and rename the new one as the original...
the way that the "archive manager" app is probably doing this is a bit more advanced and I wouldn't bother trying to emulate that behavior in bash, but that doesn't mean that you shouldn't try...