Penetration with wood shafts

We had a period where we used the laminated birches. When they were right for the bow they were good, I found that they liked a lot of feather drag and had a fairly short forgiveness window as in loggy versus acting under spined. They did give great penetration when everything was right for them.  My wife hated the weight and the length her's needed to be.  The problem I had with them was the crossover from target points to broadheads.  I needed longer lengths to satisfy lighter narrow target points and shorter for 160 grain broadheads.  I always set up my arrows so my broadhead just tags my finger at full draw, I have my wife doing the same.  It is one part of our form that I will not give up.  I see quite often when archers lose a bit more draw than they realize when shooting at game or targets that spook them.  We are no different, but having a draw check that is always built into the arrow has become a standard for us. With arrows that are around 27" bop it is very difficult to get some shafts to tune.  I find that the narrower aluminums work better than the fatter ones.  The 18 and 19 size aluminums is all I will use for bows 60 pounds and under.  I do believe that a 1920 and an 1820 has more penetration potential than an 11/32" cedar, but wood still works on whitetails in Iowa just fine.