First option.
You could copy this formula into col G, next to each branded product
=INDEX(All!$1:$65536,MATCH(F4,All!A:A,0),MATCH($A$1,All!$1:$1,0))
And then into your yellow D11
=SUM(OFFSET($G$1,0,0,MATCH("Marvel",F:F)-2))
(This will allow you to do other sum in col G - eg if you wanted to count marvel/platform products)
This may be a bit labour intensive as it involves adding the formulae to each shop sheet. I can try to work it into a 1 formula solution if that's better.
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