I like to use descriptive zone names rather than the default trust and untrust. And create categories for each group that indicates the nature of the connections there. So in your example with two central sites there likely would be more than one internal zone at a larger site users, resources, IoT and perhaps others. Likewise the remote sites may be just user zones or might have other categories as well.
I use the same zone name for the same functional group at any site where it exists.
Also remember that for traffic from a remote site to another site requires two policies one at the SRX at each location. So the VPN setup would be route based vpn with the zone of the st0 interface for the remote site being a name that makes sense for the traffic and type of network on both sides. For example the central sites may share or have a unique per site zone while remote sites may share a name or be uniquely named for the site.
Also bear in mind scaling limits on the number of tunnels if you will have full mesh. The number of tunnels can grow fast if there are a large number of sites.