I think a distinction should be made clear between 'canon' and 'one, workable, overall plot'. I use my "canon levels" to determine which sequence of events to choose as part of the 'overall plot' when two events disclude each other.
My canon levels aren't really useful in determining 'canon'. Canon has nothing to do with 'this contradicts this' or 'this wasn't written by so and so', "canon" simply refers to a collection of works considered to be the accurate versions of said works, or the most important in a specific field.
The fact is, there is no 'Dragon Ball canon'. Such a thing is simply non-existent. The author doesn't care, and has basically washed his hands of the whole thing. The production company just sends out everything as "official", so they're no help. The only option left is for literary scholars to decide what parts of the franchise are, and aren't, suitable as being studied and categorized as 'canonical'. That won't happen, if at all, for several
decades - that's how literature works. Slowly.
Here's the bottom line: there is no 'canon'. No amount of argument will change this. If you would like to discuss the relevance or workability of a specific plot point, movie, or sequence then argue about
that - whether or not that fits - not whether it's 'canon'.
Oh, and no 'move at light speed' arguments either. 'K?
