Sorry but your assumptions are incorrect. That being the case why dont you recognise your limitations and hire a professional to review the proposed strategy.

Please don't take offence as none is meant but your question doesn't really make sense? Firstly you mention fire strategy design documents that have been provided by contractors that are tendering for some new buildings. Then you mention Approved Document B and BS9999 IMO contractors would not include design documents for fire strategy - that would be a role of the Designer in coordination with CDM-C and Client (end user) if a notifiable project. If not notifiable there would still be a designer and client who would need to organise the fire strategy for the finished product. A contractor would submit plans in advance for the fire safety aspects during the project but that would not need anything out of App Doc B or BS 9999. The Principal Contractor would be responsible for the construction fire risk assessment/s in accordance with the rrfso. Whatever guidance is used the end user has to provide a fire risk assessment according to the rrfso therefore the design of the premises has to ensure a suitable and sufficient fra can be carried out without need for any building alterations, therefore the rrfso should be consulted along with whatever other document, and that should probably be Approved Document B. British Standards and Approved Documents are not requirements and information can be gained elsewhere to carry out the work but you must ensure Building Regulations are observed.