Generally *A programmes operate on a mileage basis rather than sectors and points like BA do where QR LHR-DOH-BKK makes earning silver easy. The result is that it's the earning on the fare that matters more than sectors. Some airlines offer better multiples in business than others and some offer nothing at all on their reduced business fares - watch out on that one for Lufthansa unless you are looking at M&M which grows ever more mean. Look at wheretocredit.com for some of the best advice.
Generally one of the most generous airlines is TG so easy for BKK where you earn 200% on most fares in business. Compare that to BR and you earn 125% - though BR offers a service which is at least as good if not better than QR.
Which programme are you looking at? It's easier to be specific if we know a bit more.