This mod is a total overhaul of the AI. It covers a wider range of difficulties than vanilla, all of which play in a more humanlike fashion than their vanilla counterparts.
Download the Queller AI for Planetary Annihilation - Exodusesports.com
The Queller AI (yellow) fights the default AI (white). This isn't a perfect comparison because there's an AI file called ai_config which differs between the two AIs but has to be shared. In this instance the default copy was used.
This is a slightly modified version of Queller 1.2.4, so there may be some odd behaviour from changes which haven't yet been fully tested.