I guess that's an interesting...extrapolation about their dynamics, at least in so far as you can take fan art as an indication, but one always requiring a huge grain of salt.
I think it might be fair enough when it comes to Suzaku still being angry at Lelouch and not even regarding him as an actual person though (assumed brainwashing included). Such an attitude on Suzaku's part would make sense during this period of time, especially since I'd speculate he isn't very happy about the whole idea of accompanying Julius either.
That said, I believe the "overconfidence" has more to do with the fact Julius comes out of the train and makes a grand public boast like Zero/Lelouch used to do. Even the newest trailer manages to convey a little of this, if you've seen it, but it's also been mentioned by people who saw the episode. And well...travelling on a train isn't equivalent to living in the same place. But I can see why some fans would jump at the opportunity to read too much into that. Can't deny this is all good for marketing purposes either.
