Never rely on your good relationship with the landlord to protect you if future problems arise. In a few months time, landlord might sell the freehold of the building to someone else, who may turn out to be a very different kind of person. You should always make sure you negotiate all the best protections, just in case.
Landlords usually own the freehold of the building where they are granting leases. But that’s not always the case. Sometimes landlords may themselves be tenants under their own lease – called “the head lease”.
If that is the case, the landlords won’t be able to diverge in their deal with you from the terms imposed on them. You and your solicitor ought to see that lease to understand the landlords’ scope of movement, and to make sure the landlords will be able to comply with their own lease.