Yes, but would more engines have helped in that case? If that problem stopped both engines, chances are the same problem would have stopped all 4 engines on a 4

Yes, but would more engines have helped in that case? If that problem stopped both engines, chances are the same problem would have stopped all 4 engines on a 4 engine plane as well. So you'd need to look at cases where independent failures cause both engines on a twin engine plane to fail. I'd guess those are quite rare.