Seeing a lot of threads of people comboing the 221s and 225s. If you go to Mizuno’s website in the Mixed Set recommendation page, they recommended bending 225 7-iron 1 degree weak, 221 8-iron bent 2 degrees strong, and 9-iron bent 1 degree strong and PW standard.
I almost did this too for aesthetic reasons, but eventually just did all 225s since I don’t want to reduce bounce especially with blades in Northwest weather conditions which plays mostly soft throughout the year and afraid with reduced bounce increase risk of digging into the turf.