You haven't indicated which particular flavor of "Tri-X" you are comparing. Specificity helps a lot in attaining a targeted answer to a question. And that helps me in helping you as I only assist where I have a lot of personal experience.
I use both HP5+ and TXP 320 in 5x7 interchangeably for similar kinds of work, both shot at 200 (arrived at by my own film testing). I develop both in PMK Pyro as that allows me to obtain the finest grain and proper contrast (for me) in these films, given that the film is properly exposed for the scene (zone). I tested many developers with each of these films, based on my own desires, before standardizing on pyro.
I find HP5+ to have more contrast and slightly finer grain than TXP – so fine that I cannot grain focus under the enlarger at less than 20"x24". But for the purposes of enlarging a 5x7 negative to anything less than 40"x60", the distinction is negligible.
Yes, developer and process (agitation) make a difference, but proper exposure and recognition of light for the scene trumps both in terms of contrast.