If you’re concerned about EMC, then this is a very good video. It’s a tad long (over two hours) but it’s worth it.
at around 1:40:00 some 4 layer stackups are mentioned, and the (simplistic) conclusion is more ground is more better. 
If you’re concerned about EMC, then this is a very good video. It’s a tad long (over two hours) but it’s worth it.
at around 1:40:00 some 4 layer stackups are mentioned, and the (simplistic) conclusion is more ground is more better.