I agree a lot of the attacks on Russell and Rutherford focussed on personality rather than theology. Because I’ve been reading church history, it reminds me of how Athanasius attacked the character of Arius, even implying that his untimely and ignominious death (possibly involving sudden gastrointestinal symptoms) was a divine, or at least just punishment. It has also been suggested Arius might have been poisoned.
I have the impression that Russell was generally a kind person who got on well with others. Hundreds of people turned out for his funeral and were genuinely upset, including apparently his ex-wife—despite their acrimonious divorce—who laid a flower on his coffin. People who knew him well, and those who met him only briefly, alike seem to have been left with favourable impressions.
Rutherford on the other hand seems to have been disliked with good reason. Even his allies tend to talk about him in terms of respect rather than affection. I think it’s possible that his experience of prison, and subsequent ill health in later years, made him a harsher person than he would otherwise have been. But plenty of people suffer adversity and still manage to treat people kindly. If there is any truth to the claims that he all but abandoned his wife and had affairs then that’s a whole other level of nastiness.
About the footnote, it sounds like it was better to stick to the scholarship, unless the criminal behaviour was directly relevant, but it’s hard to know without the full details of the situation.