Two or more authorized insurers may together issue:
(1) An underwriters policy bearing their names upon which their liability shall be joint and several. Any one insurer may issue policies in the name of an underwriter's department provided the policies shall plainly show the true name of the insurer.
(2) With the commissioner's approval, a combination policy which shall contain provisions substantially as follows:
(A) That the insurers shall be severally liable according to the terms of the policy for the full or specified amount of, or percentage of, any loss or damage aggregating the full amount of insurance under the policy.
(B) That service of process, or of any notice or proof of loss required by the policy, upon any of the insurers executing the policy, shall constitute service upon all such insurers.
This section shall not apply to co-surety obligations.