First, I have a habit of using ‘But’ to start a sentence that contrasts or contradicts the one before, or, perhaps better, the expectations that that sentence raised. ‘But’ does the job wonderfully and makes the resulting paragraph much easier to read aloud fluently. On this occasion, all such ‘But’s became ‘However,’s.
(There seems to be no very plausible story about why using ‘But’in this way is so widely spurned. I am not at all surprised but a good reason would make it less weird.)
Second, when I do use ‘however’, I move it to a point in the sentence after an initial clause and where a breath might actually be called for. Given that such a sentence-starting ‘However’ needs a comma to flag that it doesn’t mean, eg., ‘however hard she ran she could not finish’ it produces a clumsy staccato effect.
The two together produced a text which, absurdly, couldn’t make up its mind. (Odd that whatever faith the editor had in his or her own rules in each occasion he or she did not think that the result of their joint application suggested anything was wrong.) But in repairing the damage, I felt a little bad about simply returning every case to my original formulation. (I am not that proud of my writing.) Instead, I returned a generous third of cases, left a mean third as corrected by the editor and simply deleted the connective in the rest. I suspect, in other words, two things are the case. Either, I over flag changes of direction which the reader would be perfectly able to grasp. Or, my sensibility has now been utterly corrupted by reading my own text for more than an hour.
