One way for the PCs to acquire soldiers and facilities could be for them to take on obligations to planet and organisations they control.
An example could be that the PCs control Corellia and wants to take over Duro. By taking on the obligation "Weak defence at Corellia" the PCs gain a attack fleet. The the obligation can be triggered by an imperial fleet approaching Corellia. The PCs would then have to either defend Corellia or lose Corellia. This can be scaled, at the start of the campaign it could be recruiting freedom fighters in a village.
Faclities could be gained in a similar way, except the obligation would be to supply the facility with material or personnel. The obligation could also be a debt. E.g borrow money from a trade consortium.