BE 2012 is server-centric and in most cases, you end up with at least one job per server. This means that it is more a chore to schedule your jobs.
You can start all the jobs on or about the same time, but you would not be sure which job runs first and which runs next. This has serious implications when you want to overwrite a tape and then append to it. Setting job priority will only be of use if you have 5 or less jobs.
To make sure that the jobs run in the sequence that you want, you can schedule the next job to start some time after the preceding job ends. This means leaving a gap between jobs. However, if your backup window is tight, this method is not desirable.
The other way is to use BEMCLI to chain your jobs. Before you can use BEMCLI, you need to setup your Powershell environment so that it can run BEMCLI and scripts. See my article on how to do so.
The above command will get the list of jobs, select only scheduled backup jobs and write their names to the file, jobs.txt
Use The Post-Command To Start The Next Job.
Once you have decided on your sequence of jobs. Put all the jobs on hold except for the first job, then edit each of the jobs in turn to put in the post-command to start the next job. For example, in Job1, put the post-command to start Job2 as follows