If you study the corpus of letters attributed to Paul, then you need to read Nijay K. Gupta's recent post, How we analyze ancient texts - are we letting the cart pull the horse?

Nijay is looking specifically at 2Co 6.14-7.1; but his comments apply to various portions of the Pauline corpus. Of course, I see immediate application in the Pastoral Epistles, going back at least to P.N. Harrison's 1921 volume The Problem of the Pastoral Epistles. Nijay goes on to suggest a three-pronged approach when dealing with texts that seem difficult in their current context:

(1) Analyze the text as is and try to come up with a rhetorical scenario that can account for the flow of the text

(2) If this seems impossible (as in the transition to chapter 10 of 2 COrinthians), consider historical scenarios that can account for this without assuming redaction: So, Paul may have heard some distressing news between finishing chapter 9 and beginning chapter 10).

(3) Consider, but only tentatively, other options that involve later and non-Pauline redaction.

You really should read Nijay's entire post. I heartily agree with Nijay's suggestion that the text as received be analyzed first.