I’m not in the insurance business, so others who are might have a different view, but there is an economy in using the same company for all coverage. These high end insurance companies insure valuable art, yachts, etc. and are used to dealing with specialized items of value.
The flood insurance is a whole other thing--my recollection, when we lived on the Hudson River, was that the only flood insurance available for the structure was the government associated "FEMA" type. For the possessions, I’d have a discussion with the broker about how the various insurers cover when there is a risk associated with flooding. We did have "flood insurance" but again, my recollection is, it doesn’t have a high limit and we were being overly cautious- during Hurricane Sandy, several properties along the river were destroyed. We were on the mountain (high) side of the road and suffered no damage that I recall, to structure, grounds, or contents.
The flood insurance is a whole other thing--my recollection, when we lived on the Hudson River, was that the only flood insurance available for the structure was the government associated "FEMA" type. For the possessions, I’d have a discussion with the broker about how the various insurers cover when there is a risk associated with flooding. We did have "flood insurance" but again, my recollection is, it doesn’t have a high limit and we were being overly cautious- during Hurricane Sandy, several properties along the river were destroyed. We were on the mountain (high) side of the road and suffered no damage that I recall, to structure, grounds, or contents.