I would be very surprised if this wasn't' a case of GEICO acting only as an agent/broker on this policy. It is possible the ultimate carrier was a different BRK subsidiary but seems more likely to be an unaffiliated third party.

This was the case when I used Geico for my first home. But what was worse was they didn't partner with a reasonable third party. The insurance gave me what I didn't realize was a we don't want you quote.

I had Geico car insurance & had used them to get renter's insurance, so they were my go-to when I needed homeowners. At closing the closing agent said "is that really how high your insurance cost is?" Not having a frame of reference, I explained it was insured for replacement value. She said "still, it's high".

After closing they sent me a ridiculous list of conditions for keeping insurance. Thinks like cleaning some green staining off the brickwork, and cutting the 60-year old sycamore trees away from structure. The tree requirement written in a way that suggested complete removal. We had a certified arborist look at them, and they cut away any dead wood, and trimmed a 10-foot clearance from the house (the larger limbs still overhang the house, just 10+ feet above it). The arborist was like "so, your insurance is concerned about these trees that have always been here?"

I took before and after photos of the scrubbed bricks, and of course had the invoice from the arborist to submit to the insurance, but meanwhile I had shopped around, and everyone else was half the price. So I just got new insurance.