You should only check for null
when it's supposed to happen, for example in a function that takes an optional parameter.
When in your code you're dealing with null
when it shouldn't be there, you should let it crash so you see exactly where the problem occurs, else you will delay and hide the issue and make it harder to track the origin of your bug.
If you're facing initialization order problems, try to initialize later or add methods that finalises init so you're sure everything's in memory, a good place would be in the manager that creates both of your objects.