Sounds like your a 4am store, I'm assuming the powers that be assume unloading at 330pm is a good idea to get a jump on the truck. First off, its not a good idea, second if your struggling to get done when the early morning crew comes in then its not working since a lot of the work load is done already for them. It makes no sense to have 7 people unload and work truck plus the closing teams normal duties.
Quick run down:
you should be unloading at 4am, 1 hour to unload and if you cant meet that goal you need more people unloading(review best practice, it will help), after unload 30 minutes to finish bowling whatever departments you are going to work before store opens. Wave stock the truck when store opens you should have a clean floor and working off flats and tubs. Your team should be able to get out close to lunch or shortly after depending on truck size, time of year (BTS is a killer) and size of team. Now your repacks you can have a repack wave, or a person to break out repacks and stage in aisles to be worked with freight either way works but usually one way works better for different stores.
4am process for backroom, they should be doing the autofills, backstocking the blackline from the truck, and then backstocking what the flow brings back. Depending on how many people you have and how quickly they get done they could even be on the floor helping the flow team to push (my team generally does toys).
Your dayside backroom should be pulling cafs and some stores have them work them as well, it depends on volume and staffing. The salesfloor should be dealing with reshops.
I hope this helps but honestly as long as your unloading at 3:30pm, and trying to push the truck, reshops, cafs and zone your just making it more difficult on your team and yourself. If you choose to continue to do that then like I said when the 4am comes in they don't have unload so technically they are already starting an hour ahead, if they cant finish or their struggling real bad then you either need more people or its poor leadership.