I typically have teams that run man defense. I have a D3 team that I switch to press to give that a try. With that said in man if a team has a dominant scorer and I have a good defender in another position I might switch my good defender to match up with their best scorer.

My question is, does defensive match-up even matter in press? Or is press defensie more of just a total sum of the defenders I have on the floor?

Match-ups matter. Think of the FCP as a double-team everywhere.

defensive matchups do still matter IMO. i still move players around in press when appropriate. its not quite as important as man, or at least there is more going on, other considerations... for example, i don't think there are any matchups in the full court pressing phase, while the position of your presser does matter (pg/sg speed matters more to the team fcp for example than sf which is still vastly more than pf/c).