Should be a simple one- in battle of the gods games (where all techs are researched at the start) the AI still builds research buildings and tech capitals etc. Presumably they are also diverting part of their tax income to research too. They continue to value trade goods that boost research too, and mine research resources.
Even wierder- remember the issue with tech trading in normal games, where all the AI end up using the same weapon type? They do that in battle of the gods too, despite having all 3 to choose from.
Any chance of sorting this?