Gentlemen I can not sleep tonight so I crunched some numbers instead.
I'm a little bit hesitant to show my working because I used my own platoon as a case study and I believe the results may be used for good or evil, I don't know.
My casual platoon had a combination of people who did and did not do their third hits, I figured out how many potential hits were missed and drew up some estimations of how many ranks we could gain if 3rd hits were compulsory.
Assuming all who did only 2 hits did outpost battle and got 1600 points, (minimum considered value)
Rank gain: +6 spots
Assuming people could pull off a third pull at the same level as the average of individual best hit, (considered best case)
Rank gain: +22 spots
Assuming the 70th percentile between these two values, (presumed realistic effort)
Ran gain: +15 spots
Obviously these results are specific to one platoon at one exact rank and your results would be different if you have higher or lower competition in your bracket and depending on how many 3 hitters you have versus 2 hitters and the general performance of your platoon so this information likely means nothing to anyone, but I found it interesting.
I am not proposing we enforce 3rd hits either, this is just for analysis.