So then what did you mean when you said it is hard to be definitive about concepts of gods of which you had not heard?
Just what I said.
Look, semantics around whether atheism is a lack of belief or disbelief aside, I generally favour pragmatism over precision.
When I was 12, I was an atheist. I'd evaluated the Christian God to the best of my ability and figured out 2 things...
1) Many people who worshipped this God didn't act in a manner consistent with their purported belief.
2) Specific claims made about the God and it's nature were inconsistent, and appeared to make sense only if you thought of the God as a powerful human, more like the Greek myths I loved reading.
So my atheism was formed at a young age with dual concepts.
The God you're telling me about is one I actively disbelieve and would argue against.
The concept of God is one that appears unrequired and unsupported by evidence.
Make of that as you will, but I've never hidden behind those concepts as a way to justify my atheism. I merely see atheism as a broad label encompassing many.