I found the readme and it starts as follows:


Monotype is a trademark of Monotype Typography Limited registered in
U.S. Patent and Trademark Office and certain other jurisdictions.

Arial is a trademark of The Monotype Corporation registered in U.S.
Patent and Trademark Office and certain other jurisdictions.
---------------------------------------------------------------------
SID MEIER'S ALPHA CENTAURI PLANETARY PACK
(c) 1999-2000 Electronic Arts. All rights reserved.

README.TXT
1/29/00

-----------------------------------------------
CONTENTS OF README.TXT:
-----------------------------------------------
1. CHANGES IN ALIEN CROSSFIRE VERSION 2.0
Fixes

2. CHANGES IN ALIEN CROSSFIRE VERSION 1.0
Additions\Enhancements
Fixes

3. CHANGES IN ALPHA CENTAURI VERSION 3.0
Additions\Enhancements
Fixes

4. CHANGES IN ALPHA CENTAURI VERSION 2.0
Additions\Enhancements
Fixes

It seems we have the planetary pack but "stripped" of Crossfire.
However it seems that SMAC is at version 3.0
Shall I update it with the official 4.0 patch?


EDIT: Well 4.0 was release in 1999, while the "planetary pack" in 2000, so "maybe" we don't need to patch

The readme file is confusing because it includes both SMAC and SMAX. However, GOG shipped version 5.0 of SMAC, so no additional official patches should be applied. Also, the readme file is wrong in not listing in the contents the changes for version 4 of SMAC. However, the v. 4.0 changes are present in the readme. They comprise the text following this:

NOTE: Alien Crossfire now contains all the additions/enhancements
and fixes to Alpha Centauri 1.0 that were contained in the
downloadable updates, V2.0 through 4.0.

I see, thank you very much!