3 child applications - can we send documents to one office?

We have three boys and are renewing one children's passport and requesting two new ones. We did all the applications online, and have just realised that each application is being dealt with by a different passport office (Bootle, Liverpool and Peterborough). Does anyone know if we can send all relevant documentation to one single passport office so that all applications are dealt with at the same time, or do we need to send each application to the address listed on the application tracker? We don't want to send them to three different addresses, as it would seem to increase the chances of one of them being delayed... but likewise we don't want to send them all to one address and then there is a delay with them being sent to the wrong address. many thanks for any advice