I'm talking about critical rate, injury, combo rate, control rate.

Those are the secondary stats.

There's also initiative, of course, but what that stat do is blatant to everybody and has anyways to be a way to select who moves first, so is the only secondary stat i would not talk about, for obvious reasons.

Yes, i know there are also nin p3netrations, tai p3netrations, damage reduction and elemental weaknesses, but i would prefer to avoid talking about them because is blatant they should not be nerfed for how low they currently impact on the battle mechanics (if possible those ones should be buffed instead...)

Anyways, you are wrong about saying that the only way to nerf them is to remove them. You can easily nerf them by modifying their impact coefficient or their availability.

Currently every 100 rate of difference between the stats of ninja 1 and ninja 2 grants a +1% bonus to the effect of the stat itself, if instead of +1% they granted a quantity lower than 1% (0.8% or 0.5% for example) you would get a nerf of those stats (a nerf to the effect of those stats).

If instead of granting 665 of those stats a level 10 refinement would grant a lower quantity than 665, you would get another kind of nerf to those stats (a nerf to the available quantity of those stats at the current price).

P.S. i'll wait some more replies, now that i better explained what i meant before giving my opinion.