I discovered all my on planet battles and space battle victories did not seem to weakend any opponent. They still had all the money in the world. Only the home planet crowded mess of an arena seemed to matter and i gave up!

Anything different about this version?

It may have changed, but I believe the AI ignores food and money maintenance of their units.
I noticed this after some special adding mercenary units (cheap to buy, expensive to maintain). AI enemies amassed crazy numbers of them, and their economy did not collapse.

Note also that the AI ignores resources for building units - it will consume them if available and even buy from the league, but if there are no resources available it will build the unit regardless. The only thing the AI respects when building units is the input unit when needed.

Edit: The AI also follows the unit build time (no instant building units). A long time ago there was a submod (built on top of Nova) that added versions of units with no resources needed but with increased build time, these unit versions were first on each entry so the AI would always select them instead of the resource using versions. This submod added some balance to the AI versus the player, and the player also had the option of building the units quickly using resources or the AI way, using increased time.