If you want to sum the quantity as a count of how many items then I would recommend:
Create a line item in the module called 'Qlikview Competitive Take Out Report' and call it 'Count' and make the formula '1'
Then in the module called 'CTO Competitor Categories Report Details' under the line item 'Qty' create the formula that does the following - references the 'Count' line item and then sums the category dimension (so the name of the list for the categories) - Like Qlikview Competitive Take Out Report.Count [SUM: the list in the line item called 'CTO Competitor Report Category', LOOKUP:Quarter Year ]
Alternatively I would look for a way to link the data to the anaplan time dimension quarters in the module 'Qlikview Competitive Take Out Report'. This will mean you do not need to reference the time via a lookup such as you do in the 'Quarter Year' line item.
In the take out report, create one line item formatted with Quarter List you are using and derive the quarter using the PARENT(ITEM('List Name')) formula. Create another number formatted line item called Count with the formula of 1.
Then use the following formula in CTO Categories Report Details module: Qlikview Competitive Take Out Report.Count[SUM: Qlikview Competitive take out report.CTO Competitor Report Category, SUM: Qlikview Competitive take out report.Quarter]