I've also had overly entrepreneurial investors in the past. Just like you being a first time entrepreneur I had paid a lot of attention to my investors ideas. Knowing that they had success and experience in their own businesses. In the end I ended up wasting a lot of time by ignoring my gut feeling to just say no.
Honestly, it is always good to get advice (from almost anyone) and one should be respectful of their investors time and money devoted to one's business. With that said, I've learnt to discuss investor advice in regards to my product and customers. As the entrepreneur you will be the one spending the most time on your business and customers. You have been building up a domain knowledge that your investors will unlikely have been matching. So better listen to the actions of your customers. They should speak louder than your investors ideas. At the same time your investors will have their own agenda, if they say you are thinking too small then it is perhaps them talking to themselves, however it may not apply to your situation in that moment.
As has been said by the previous commenter, build a formal process where you can discuss once a month the strategy. Listen to their ideas. But be prepared to say no. In the end you are running this business and in order for you to be able to run this business you need to have the ability to execute.