When I did the lift on my truck years ago, I was asked the tire size I wanted which is 31's. The tech said 4:10 is the ratio that suits 31's just fine. Since I have the 3.0 & the 4:10 my truck has never had anykind of power issue since day 1. No drop in gas, get up & go, or driveability besides 4:56 was more expensive so I settled for the 4:10. Over the years even on TRS & RPS 4:56 was a better gear if you are running 33's or bigger.
Since I have been using the 4:10 on my 3.0 2wd ranger for around nine years now, I will go ahead & put 4:10's in my other ranger. That is a good setup for me, & it does real good at least for me anyway. My 3.0 is not weak with those 4:10's since it has the 5spd. It can & will get out of it's own way.
Why do you think 4:56 would be better on the 3.0 than the 4:10?
Where did you find that 4:10 gear is wrong for the 3.0?