No not a derailment
There was a time when Rangers were kings. Ranger/Monk splashes (particulary halflings) with Wounding of Puncturing rapiers would tear through all content and really only needed help with bosses. Alacrity meant that they could stat damage faster and dex based meant high AC finesse builds that could outkill anything. It was not uncommon to see 6 splash Rangers in most melee builds. At that time the Vale was end game and the number of FE needed was few as almost all major bosses/threat types were evil outsiders, constructs, elementals, undead and probably whatever gnolls fall under. The problem is ever since that time all they have had is nerf after nerf. There is absolutely no danger in things going back to Ranger dominance again and that is a good thing but many of the reasons for many of the decisions that have altered combat in this game have gone.
1. DPS is king, Rangers while killing machines were never the highest dps in town and finesse based were worst. Now with vorpal nerfed on top, you are never going to see a top end killing machine that is dex based.
2. The complete nerf to AC (exploiters) this began with a poorly justified introdution of Grazing Hits that has led to the must have max hp and max heal amp view of things. Both of which downplays the potential of a ranger particulary a splash build.
3. The typing of the Ac bonus to shield was to nerf the high AC of ranger splashes compared to other builds particulary s/b, now with bonuses to SD and DOS who get a stacking AC bonus higher than tempest this is not really needed (not to mention massive hp bonuses)
Now the introduction of Damage Reduction % for defender type builds using shields (very much needed as these were really suffering) and monks (who have not been wanting for some time) and would provide a nice supportive ability for Tempest who are given a defensive buff yet not always able to make the most of it. This way those who dump their dex and go str/con still get some benefit and those who splash for AC can do the same.
I believe that major positive changes will happen with the enhancement changes, what we have been shown for rangers (very early) looks very good. However we have no idea when this is going to come in and regardless the changes suggested use a pre exisitng concept and would add value without coming close to OP while we wait for the big update that is long over due.