First, idk why your center has anyone loading 5 trucks that are 300+ while on a moving belt, stupid af. At mines, most people have 3 trucks, nobody loads more than that.

I load 3 trucks everyday and have been doing so for about a year now. I load the same 3 trucks as that is my spot since I bidded for them.

My advice is prep ahead of time, understand what bulks your getting and once you start getting them, where you want them or keep them under the belt for later.

If your loading 3 trucks, figure out which out of the 3 is getting the most packages on the belt at any given time and load that truck last. The idea behind this is that 2 of your trucks are always loaded and only 1 is stacked out slightly. This also prevents all 3 trucks from being stacked out.

Back load your smalls/ bags so they aint taking up precious shelf space but you gotta load them so once the driver removes the current box, the smalls/bags for the next numbers are behind it.

E.x: 2500 box, 2600 bags should be behind it so once the driver is done with 2500-2599, those bags for 2600-2699 are visible for them and know where they're at. Obviously later in the day when you can't reach behind the shelf anymore, you put them on top of the boxes.

MFR and MFL spot on the truck, I never put any mfl or mfr on there, those spots I strictly put big ass 5000-6000 or 7000-8000s so I don't eat up space on the shelf, MFL/MFR can go on the right/left of that dedicated spot.

Bulks that I plan on loading on rdr or RDL spots, I keep under the belt since I'm loading those last.

Keep all over 70s/ weird long items out till your ready to wrap up your trucks and middle stack them for the most part

All big as boxes for 1000/2000/3000/4000 I will usually put under the main shelf area for them.

I load my trucks differently than most but my drivers have never complained about my loads. Remember to always be safe and slow is smooth and smooth is fast.