Is there any connection between the fact that Atticus does not conform to his children's view of 'manliness' and his intention to defend Tom Robinson in the forthcoming trial

I suppose that not conforming to societal norms in the eyes of his children does have a connection with his defense of Tom Robinson. In both cases, Atticus does not do the popular thing or pretend that his actions are any different to how he really feels. If anything, Atticus is true to himself and his actions are no different than what he stands for.