I doubt there is THE answer/solution. There are best practices which I doubt they fit for the majority of startups or small businesses.
It always depends on your stage, workload/actions, staff (men-power) and priorities. The schedule you and your advisors feel comfortable with is the right schedule.
In the position of the founder/entrepreneur, I would try to keep things for my advisors as smooth as possible and don´t stress them by "forcing" attendance to meetups/confcalls that doesn´t require their expertise or attention - which should be obvious.
Therefore it depends on ...
Not sure if this an answer to your question at all - but this is what comes into my mind.