Yithril also has -1747 gildar. Wouldn't all of his armies have abandoned him by now, too?

Yithril is always the lead AI. If this is happening, that would explain why!

It's been reported by other people that the AI doesn't need resources to build units. Which is not great, but I guess that might have been the only way they could get it to give an effective challenge. It does seem to give a pretty massive advantage to AI nations which rely more on troops. It would be nice if they could fix this so the AI is playing by the same rules as the player (or closer, anyway). Even if they gave the AI a few thousand of each resource at the start of the game on higher difficulty levels, it would feel less like cheating than just having the AI not need resources to build units.

I've also seen the AI offer zero credit for resources such as metal, however I don't think this is a bug. In all the examples I've seen the AI gives zero credit for a resource it has lots of. So in other words if it has 400 surplus metal it will give you zero credit if you offer more metal. Why exactly would you expect it to give you credit for offering something that it already has more of than it knows what do with? It will offer credit for a resource which it doesn't have much of. I don't know exactly what the cut-off is, 50 or 100, maybe.

I think it is important to also note what difficulty levels were you playing on when you noticed this problem. Higher level difficulties are given the opportunity to cheat, while lower level difficulties are to be given a more equal experience.

Hmmm, thank you for posting a screenshot.  I had seen people reporting this but didn't know you could look for that information on the Foreign Relations screen.

In my game Hard/Hard, turn 161 I see that Yithril has -210 iron, Magnar has -21 Mana, Pariden has -30 Crystal, and the three other AIs (Tarth, Kraxis, and Resoln) have all their stats above 0.  That explains how Yithril's power level got so much higher than mine (even though I am in second).

It's interesting to see that all the AIs aren't cheating with resources; and that the ones that are are cheating in different ways.

On top of that, I have found out that the AI keeps buying (rushing) units and buildings - since it does not have to care about gildar, why not. That's what creates the problem of overdeveloped cites surrounded by swarms of units. The actual rules of the game (i.e. earning what you spend first) would never possibly allow an actual player to accumulate such assets in such a short time.