Group rides differ between areas and conditions. Our area has a mix of flats and hills and they are spaced in such a way that we can get in 40 miles with little or no climbing to speak of or 30 to 40 miles with 3 to 4000 feet. I don't do 4000 feet very often because I climb like a snail. But I have noticed that your perception of being in the first 3rd of a pace line is a lot better than the last half is a trueism.
What I was trying to relate to is the lesson sometimes it is better to finesse your ride than try and muscle your way through. It has been a long time since I felt one with the machine and I think being down on power was one reason I noticed it.