Signatures

Tenancy Types and Management

Hi,
I am about to let a property to a couple where the man works away for extended periods and is not due home before the tenancy begins. I am sure that I can get the tenancy signed by him via post but I have a question regarding other documents. Once the Tenancy is signed by both parties, is it ok for things like Inventories (Covered by lead tenant clause I know) key receipts,health and safety info to be signed by one person only and if so would the other tenant be bound by them under the joint and individually clause. Is ther something else that can be added as an addendum to cover this?