If I understand the question correctly (which I am not entirely sure I do), I think the answer is a sense is yes...
If you follow the very cautious and controlled process of the link:
http://www.zen-cart.com/entry.php?3-...d-of-upgrading, at one point the ZC 1.5.4 (when upgrading to that version or the latest version) files will be at the location of the old site. (Remember there are a number of ways to locate/relocate files, copy, rename, move, etc...)
But to perform the database upgrade portion, which is sort of like the last step when applying the upgrade to the live site, requires the zc_install folder to be at the root of the store path that is being upgraded. (The zc_install for 1.5.4 should only be run against store code that supports 1.5.4. )
Basically, step by step in the guide, understanding that some of the early discussion is just that, discussion. Concepts about how the whole thing fits together... Read and understand first, then apply... The task will go much quicker (less errors) when approached with understanding first.
Sorry, long msg. :|