Shopping centres are indeed a slightly different beast. If it's sprinkler system is to full life specification and has both shut off valves and flow switches at the entrance to each unit then the landlord could say the tenant has control and wipe their hands of it, but in practice as it's fed off the common valve sets many will carry out the maintenance lock, stock and the tenant is only responsible for the cost of configuration of the system when they fit out the unit or refit it.
If the centre is an older beast and there are no shut off valves and flow switches the tenant has no control other than assessing it's coverage and it falls on the landlord whether they like it or not.
Some large units ('anchor tenants') are almost self contained and can have their own independant sprinkler systems and their own valve sets and water supplies - they are wholly responsible for maintenance.
However, whatever the responsibility for servicing as an incident in one area inevitably could impact the other the landlord should really check the tenants are carrying out the minimum benchmark maintenance via co-operation and coordination visits and this forms part of our FRAs, we used to do them under the FPA (due diligence for the certificate holder, i.e. landlord) and still do so under the RRO.
A lot of FRAs in multi-occupancies, including those by specialist firms often ignore the existence of anything outside their clients area and this is quite dangerous.
Personally I'd prefer a more explicit requirement for landlords (and their agents) in multi-occupancies to take an umbrella responsibility across the premises to ensure that each occupier is aware of their responsibilities and that they are carrying them out, as at the moment approaches vary with several agents being very pro active whilst others try to do as little as possible even neglecting their areas of direct responsibility
Co-operation and coordination