I haven't played this game in a long time, and I want to play it again for a bit. I need to know about patching/upgrading to the latest version.

My last save game was made on 10/30/2014 (just for reference - I'm not trying to continue from that save)
I believe that I was playing from: patch_age_of_wonders3_2.2.1.12
I apparently downloaded and installed patch_age_of_wonders3_2.2.1.13 on 12/4/2014, but I never played after that.
The launcher says that I am using build 13052, or maybe 1.3052

In my GoG account, it doesn't appear that I can patch up from my last patch to the current version. Apparently I need to download the full installer of the latest version. If this is correct, can I install this latest version over the top of what is already on my computer, or do I need to uninstall the old version before installing the new version?

Edit: I probably should have put in the subject that this question is for AoW3

Thanks for the help. I'm currently playing through the game under the old version, as I try to refamiliarize myself with it. When I finish this playthrough, I'll check out all the patch change logs, and then probably update.