One of the arguments that is often made, when it comes to suggesting a passage in Paul’s letters (or any letter) is an interpolation, is to say that such a passage could be lifted out of the text and the letter would resume without a hitch. This implies that an editor of some kind stuck the text into the letter without much interest in smoothing out the flow of the text. This is certainly an odd practice of an ambitious editor.
In reading R. McL. Wilson’s commentary on Colossians, he addresses the issue of the household codes (3.18-4.1) and comments that some have proposed this to be alien to the original text. One of the arguments for it being an interpolation is that 3.17 could connect to 4.2 with no concerns logically. Wilson counters: ‘The fact that a passage could easily be omitted does not mean that it does not belong, or that it is an interpolation’ (273). This simple ‘duh’ kind of statement, though, needs to be remembered more in such debates!