3900 Peering SBC Setup advice

Hi

I have planning to do for implementation, Oracle 3900 in HA peering

Cal flow was supposed be CUCM <--> SBC<--> Service Provider

but now there are 500 other IP PBx's that i need to route via the SBC to the Service Provider, CUCM and to each other

Could i use a LRT table for this?

So my 1 local Policy to route calls to the 500 IP PBX's from any realm  would be

                                                                                                   

                                                                                                      from *

                                                                                                      to LRT Table of the 500 stores

                                                                                                              Next Hop would be the LRT as well based on the to Field

and a second Policy         from LRT of the 500 stores