[Edi]

The AI seems to do fairly well with independents at strength 7 and impossible AIs, especially if it has good scales (happens sometimes). Indies 7 means you need a lot more troops to beat them than indies at 5, and the AI resource and gold bonuses mean that it gets going pretty fast. It's not at all uncommon to get swamped by two or three hordes while you're still trying to get basic things done.

I play with the Better Independents mod and difficult research, so that slows me down a lot more than it does the AI.