Insurance question about office tenant

[Chris Sweeney]

I have 4-unit property that has a spare room we rent out as an office. The current tenant is a videographer and doesn't have any visiting clients (minimal liability). A new prospective tenant, a therapist, would have visiting clients, which means increased liability.

Is there any benefit to upgrading from a regular residential policy to a commercial policy for the whole building, or is simply requiring the new tenant to list us (the property owners) as additional insureds on their liability policy sufficient, making sure they carry at least $1 million in coverage? I'm thinking the latter is fine, as coverage is coverage, whether I'm the policy holder or not, just as long as we the owners are listed as insureds or additional insureds. My insurance guy recommends getting a commercial policy, but part of me can't help but think he just wants to sell me more insurance.

Thoughts?