You've unnecessarily complicated a simple point - but of course it's about tax relief, as the Tories cut benefits to fund lower taxes for the rich.
OK, let's play. You either give poor people a million pounds or you give rich people half a million. Do the rich need another half-million? No. How are they going to spend it? Where are they going to spend it? Villas abroad? Holidays abroad? A yacht? Lots of work for the UK there.
http://www.superyachts.com/directory/yacht-builders.htm Even canal narrowboats are now made in Poland.
Give it in benefits and most of it will be spent in Britain, a lot at 20% VAT (a regressive tax that proportionate to income is higher for the poor than the rich), in shops where the workers on their meagre wages will buy other stuff in Britain.
Is that complicated enough?