This was very helpful. I've been wondering about the same question. I've been playing Moderate at Level 5 and find myself significantly outscoring the AI.
Glad it helps! The score can be misleading sometimes, but usually a least one of the AIs outscores me on difficulty 7.
Though I am struggling with metal (I've got 500+ ships or so) I've got almost 200k crystal and the waves being sent after me are annoyances and nothing more (at most 20 ships at a time). It seems that though I am a newbie it's time to crank up the difficulty and see how well I fare afterwards.
Yeah, definitely sounds like it. By the way -- if you have an excess of one resource and need another (between metal and crystal), you should focus on adding some metal or crystal manufactories. The efficiency is lower overall, but it can get you something you need in exchange for something you don't need.
Thanks for pointing this article out!
You bet!