Best practice for remote office jobs

[all_around]

Site A --> primary veeam server and storage
Site B --> 2 x ESXi server, 11 vms (will grow to around 24), local vm data storage, no storage for veeam
Site C --> 1 x ESXi server, 4 vms (will grow to around 24), local vm data storage, no storage for veeam

I have been asked to start backing up sites B and C, with veeam. These 2 locations fall under the same subsidiary name. In the near future, but not right now, I will create an S3 storage and either Azure or GCP, we are having a deep discovery of our backup processes right now.

For the job(s), I will be leveraging veeam tags. sitename-os type-app (standard/sql/..)-rpo-hours
I am going to install a single proxy server at each location

As for the job itself, can I place both sites into the same job? I don't want Site B deciding it should use the proxy in Site C and vice-versa. When I create the cloud storage, they will be named after the subsidiary name and associated with the proxies.

I have not used proxies before with remote locations, so will veeam associate the vms at site B with the proxy that is there?

Am I better off creating a job for each site?
Do I not need to worry about proxies until I create the cloud storage?

I have 16 other remote locations that will eventually be brought into veeam, so these 2 are my trial office.

The plan is to eventually work with our business partner, but that is down the road. I just need to meet the requirement that is in front of me right now.

[Regnor]

If you want to backup in different repositories, then you'll have to create a separate job per site. Another reason would be, that you can set an explicit backup proxy. While Veeam will try to use the best proxy per VM, it could still happen that in a single job the wrong proxy is used.

When you offload backups to the Cloud, the proxies aren't used at all. All work will be done from your primary site's repository.