Consult bevo.mercedes-benz.com. It is a rather long chart that lists compatible brands of oil for the Mercedes specification 229.5. The GLA manual allows you to use several viscosities, but 0W30 and 40 cover almost all operating conditions. My Ferrari F430 uses 5W40 which is compatible with the GLA, so I could stock just one brand (Pennzoil) and viscosity (5W40) for both cars.
The purpose of an oil change is to get all the tiny crunchies and grindies out of the oil so they don’t wear out all the close-fitting internal engine parts prematurely. If convenience is not an issue, you cannot change the oil too much. Since convenience usually IS an issue, oil change mileage can be chosen to make a compromise. I think 10,000 miles between oil changes is too much, so I change the oil myself with a frequency, that, when combined with the dealer service visits, results in an interval of 3,000 to 5,000 miles between oil changes. I ALWAYS change the filter and seal rings with every oil change. I believe that frequent oil changes has resulted in no car I’ve owned using any oil.
2016 GLA250 4matic (ordered)