You may check the policy rules for this implementation. You will create a policy with three templates, full, differential and incremental. Then, create rules to specifiy what action to be taken if start time of jobs conflict. This should work for you to some extent. Once you have created the policy, you can attach it to common selection list, and that would generate three backup jobs. So, using rules, you can give preference to full over other templates and differential over log templates. Here are some documents for your reference, with setting up policies:
http://support.veritas.com/docs/299219
http://support.veritas.com/docs/299230
Please mark it a solution, if this is useful.
Thanks