For tracking 4-10 db reduction isn't unusual for transient material, acoustic guitars, snares, vox, bvs, hrns etc.
I don't have Concrete but use Waves L1, CLA, Ele for those chores.
For mastering I use Pro-L / Ele 1-3 db at most.
Concrete would probably fit the bill, many here use it. I don't know how hard you can push it or how transparent it is.