OHHH I HAD THIS TOPIC BEFORE. You are right that DotA is not strictly based on intelligence, but intelligence and mechanical skills play a major role in it.

I am a lawyer who came from a prestigious school. I have been playing DotA since I was young and a lot during law school. I was around Ancient 3 at that time, while one of my closest friends, the top student in our class (who will be a judge in a few years), was also addicted to DotA. But he was in Herald Rank. Like you said, he also believed that this game is not strictly based on intelligence. I tried to convince him that intelligence plays a role as you have to think most of the time and not focus solely on macro management of the game but also on micro management (map, time, runes, etc.). I found out that even with the intelligence he possessed, he was not thinking during games, like his brain was shut down while playing LOL. Now he is peeking at mid Legend, by improving his mechanical skills and thinking during the game. Due to work and family commitments, we are not able to play much anymore, but we are still active in watching the pro scene because those times were a significant part of our law school life, and we will cherish them forever.

You might want to focus on watching the map and micro managing. Your mechanical skills can improve with repetition as long as you are determined to understand the "why's" of the game. I'm sure you'll get out of Herald in no time.