You can create a small job that does nothing but wait (man sleep). Add it to the sequential job stream between each process. To get fancy, you can pass the amount of time to sleep as a parameter, that way you can adjust it from ControlM without touching the script.
Actually, ControlM can execute commands, not just scripts, so you could just have it call the "sleep" command directly. Again, just insert this between each batch job in the sequential job stream.