I think SkyTeam ++ (ie., VS,9W) should have ONE European hub. Now there are more hubs than Indian destinations.
I think DL as an adult should decide between KL/AF/VS/9W who will serve India.
Goal should be to serve more US-India one-stop options. Not to have more transit hubs.
Indian passengers like things in this order.
1) Young FAs(of particular type),
2) Non-stop/one-stop to their own City (they don't like to stop at another Indian hub)
3) Latest Hollywood Movies
4) Low fares (low priority)
5) Good food (low priority)
This is the prime reason ME3 are successful and every one else is failing.
For US/EU legacies to capture that market you have to serve non-stop to their city with Young FAs and IFE loaded with latest Hollywood movies.
IMHO VS is the only carrier has chance to do well in India. LGW is better because it is cheaper than LHR.