In my opinion centaurus is very important to swordsman. If cutter is indeed red, then go with centaurus…
I did the same thing you plan to do. I used the unlock voucher for nak muy last time. I regret not getting the miko one because I need one now.
I may be biased here, but I would never recommend nak muy to any build. In my opinion it is the most useless hidden class. Please don’t hate, I’m just speaking from my experiences with it.
Edit: both gungho and concentrate buff are a bit weak as swordsman C1. You can get concentrate to lv5 and use the tiny boost if you want. The benefits of Guardian (cannot be used with gungho) definitely outweighs lv5 gungho. I don’t know how well this build does at bossing. Someone above mentioned it sucks, but I think stabbing and pierce do OK against bosses.