I gave this mod a shoot at experienced difficulty with 5 boosted IMP (level 5/6 with 85/90% marksmanship).
I'm sad to say that it was the most unbalanced and unrealistic experience I had of all 1.13 mods I've tried (almost all).
As soon as you go tactical, the only viable strategy is to lock your team in an house with some windows and kill enemies one by one prone/crouching since a kill needs at least 4/5 0.30 cal/5.56 mm hit (with full CTH bars).
The enemy seems to well know that the weapon damage system is broken and will charge you like there is no tomorrow. So in the open you will be rushed/suppressed/killed in no time even in good cover.
Also the CTH version used is somewhat mysterious with clear in range shoots on proned enemies rated at almost 0%. Since I started to play JA2 in 1.13 long time ago, I've never used OCTH... but now I've finally understood why they invented NCTH.