Update pkg- Do we ned to recompress Parent pkg still?

We have a full pkg every 2/3 months and around 20/30 update pkgs in between.

I know that the update pkgs , update the parent pkg directory.

So for ent server, if there is a scenario needed for roll back, we can just deploy the last full pkg , and do not need to again deploy all the update pkgs that were built on top of that pkg, correct?

Now, When building a new fat client, can we do the same or do we need to again push all the update pkgs?

Or, do we need to recompress the parent pkg to do that?