Fixing my system

[Capndrs]

I'm getting furious.
I made a really basic system for an inventory that mayches my game, but it has some errors. I'll post codes first.

• Items
  • Events
    • Unit - A unit Acquires an item
  • Conditions
  • Actions
    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
      • If - Conditions
        • (Item-class of (Item carried by (Triggering unit) in slot 6)) Equal to Permanent
      • Then - Actions
        • If ((Item-class of (Item carried by (Triggering unit) in slot 1)) Equal to Campaign) then do (Item - Remove (Item carried by (Triggering unit) in slot 1)) else do (Hero - Drop the item from slot 1 of (Triggering unit))
        • Hero - Drop (Item being manipulated) from (Triggering unit)
        • Trigger - Turn off (This trigger)
        • Hero - Give (Item being manipulated) to (Triggering unit)
        • Trigger - Turn on (This trigger)
      • Else - Actions
        • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
          • If - Conditions
            • (Item-class of (Item carried by (Triggering unit) in slot 6)) Equal to Charged
          • Then - Actions
            • If ((Item-class of (Item carried by (Triggering unit) in slot 2)) Equal to Campaign) then do (Item - Remove (Item carried by (Triggering unit) in slot 2)) else do (Hero - Drop the item from slot 2 of (Triggering unit))
            • Hero - Drop (Item being manipulated) from (Triggering unit)
            • Trigger - Turn off (This trigger)
            • Hero - Give (Item being manipulated) to (Triggering unit)
            • Trigger - Turn on (This trigger)
          • Else - Actions
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • (Item-class of (Item carried by (Triggering unit) in slot 6)) Equal to Powerup
              • Then - Actions
                • If ((Item-class of (Item carried by (Triggering unit) in slot 3)) Equal to Campaign) then do (Item - Remove (Item carried by (Triggering unit) in slot 3)) else do (Hero - Drop the item from slot 3 of (Triggering unit))
                • Hero - Drop (Item being manipulated) from (Triggering unit)
                • Trigger - Turn off (This trigger)
                • Hero - Give (Item being manipulated) to (Triggering unit)
                • Trigger - Turn on (This trigger)
              • Else - Actions
                • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
                  • If - Conditions
                    • (Item-class of (Item carried by (Triggering unit) in slot 6)) Equal to Artifact
                  • Then - Actions
                    • If ((Item-class of (Item carried by (Triggering unit) in slot 4)) Equal to Campaign) then do (Item - Remove (Item carried by (Triggering unit) in slot 4)) else do (Hero - Drop the item from slot 4 of (Triggering unit))
                    • Hero - Drop (Item being manipulated) from (Triggering unit)
                    • Trigger - Turn off (This trigger)
                    • Hero - Give (Item being manipulated) to (Triggering unit)
                    • Trigger - Turn on (This trigger)
                  • Else - Actions
                    • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
                      • If - Conditions
                        • (Item-class of (Item carried by (Triggering unit) in slot 6)) Equal to Purchasable
                      • Then - Actions
                        • If ((Item-class of (Item carried by (Triggering unit) in slot 5)) Equal to Campaign) then do (Item - Remove (Item carried by (Triggering unit) in slot 5)) else do (Hero - Drop the item from slot 5 of (Triggering unit))
                        • Hero - Drop (Item being manipulated) from (Triggering unit)
                        • Trigger - Turn off (This trigger)
                        • Hero - Give (Item being manipulated) to (Triggering unit)
                        • Trigger - Turn on (This trigger)
                      • Else - Actions

• Items2
  • Events
    • Time - Every 0.01 seconds of game time
  • Conditions
  • Actions
    • Unit Group - Pick every unit in (Units of type ROBO) and do (Actions)
      • Loop - Actions
        • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
          • If - Conditions
            • (Number of items carried by (Picked unit)) Less than 5
          • Then - Actions
            • -------- Frame --------
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • Or - Any (Conditions) are true
                  • Conditions
                    • ((Picked unit) has an item of type |cffffcc00Frame|r) Equal to True
                    • (Item-class of (Item carried by (Picked unit) in slot 1)) Equal to Permanent
              • Then - Actions
                • Do nothing
              • Else - Actions
                • Hero - Create |cffffcc00Frame|r and give it to (Picked unit)
            • -------- Gun --------
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • Or - Any (Conditions) are true
                  • Conditions
                    • ((Picked unit) has an item of type |cffffcc00Gun|r) Equal to True
                    • (Item-class of (Item carried by (Picked unit) in slot 2)) Equal to Charged
              • Then - Actions
                • Do nothing
              • Else - Actions
                • Hero - Create |cffffcc00Gun|r and give it to (Picked unit)
            • -------- Bomb --------
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • Or - Any (Conditions) are true
                  • Conditions
                    • ((Picked unit) has an item of type |cffffcc00Bomb|r) Equal to True
                    • (Item-class of (Item carried by (Picked unit) in slot 3)) Equal to Powerup
              • Then - Actions
                • Do nothing
              • Else - Actions
                • Hero - Create |cffffcc00Bomb|r and give it to (Picked unit)
            • -------- Pod --------
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • Or - Any (Conditions) are true
                  • Conditions
                    • ((Picked unit) has an item of type |cffffcc00Pod|r) Equal to True
                    • (Item-class of (Item carried by (Picked unit) in slot 4)) Equal to Artifact
              • Then - Actions
                • Do nothing
              • Else - Actions
                • Hero - Create |cffffcc00Pod|r and give it to (Picked unit)
            • -------- Legs --------
            • If (All Conditions are True) then do (Then Actions) else do (Else Actions)
              • If - Conditions
                • Or - Any (Conditions) are true
                  • Conditions
                    • ((Picked unit) has an item of type |cffffcc00Legs|r) Equal to True
                    • (Item-class of (Item carried by (Picked unit) in slot 5)) Equal to Purchasable
              • Then - Actions
                • Do nothing
              • Else - Actions
                • Hero - Create |cffffcc00Legs|r and give it to (Picked unit)
          • Else - Actions

Heres what it does.
It starts you off with item holders to reserve item spots for your "parts"
Then after you receive a "part" it is taken to its reserved spot.
It destroys the holder item but drops if its a "part"

HOWEVER
because parts need to be droppable, they can be moved, which allow multiple of the same class of part in the inventory, which i dont want

Can anyone tell me how to fix this?
I made this system by scratch and didnt bother to find a tutorial on it so i dont know if theres a better one out there.