From: The Great White North!
This is a key subject and you're experimentation is a good way of understanding the game and the tactics better.
Dysta has a good point about understanding the threat and aligning your forces to best defeat it. Although I wouldn't recommend relying on maneuverability to fix the formation if the threat changes.
Setting your formation should be the result of some thought and analysis, for example:
1. What is the threat? Type, numbers, likely approach, capabilities
2. What do I need to do? Do I need to split my forces? Can I avoid the threat, or part of it, by doing things differently?
3. What is the terrain like? Above sea level, choke points, radar shadow, islands? Below sea level, depth, layer, CZ ranges, underwater ridges etc?
4. What are my capabilities, early warning, ASW, AD, do I have aircraft - type and capabilities?
Once you understand, or think you understand some of this you can think about your formations:
1.What is ideal to counter the primary threat, how do I counter a secondary threat?
2.How do I need to change that formation going: Through a choke point; approaching an underwater ridge; when I take casualties? Etc
You do need to layer your sensors and weapon systems, there is no doubt there - the question is to what extent and on what axis. Layering your AD systems may cause vulnerabilities in your ASW detection - how do you mitigate? Laying your formation to best counter ASW threats provides exposure to air threats... etc.
You've struck on a key aspect of the game, there is some discussion on the forum from time to time, but the key is to have fun with it.