I am not sure that you could even get coverage on attached units for fire insurance for individual units in the same building. You could get contents coverage, but again, if your neighbor starts a fire and does not have coverage, the whole building goes down. Not likely a HOA would allow that.
Here is a related example - Check the HOA docs for Termite coverage as well. There is a development in Simi Valley with attached Townhomes and the HOA does not cover Termite. The big problem is that If one unit needs to be tented then you have to tent all 6 units - since an individual sellers cannot afford to tent the whole building and get the adjoining units to share the cost, those units get spot treated and it is a real problem as they really need to be tented to treat the problem correctly.