I think they have conducted polls that show Harris runs better against Trump when Junior is not in the mix. Junior clearly takes votes from both candidates.
If not for Ralph Nadar, Al Gore would have won Florida in 2000, outright, regardless of hanging chads. Hence the push for ranked choice, sort of a runoff built into the first round. Voters can vent steam by voting for Nadar, but when it counts Gore still gets their vote.
Jill Stein is undoubtedly bleeding votes from Harris. I think the fear is that since Junior is a nominal Democrat, and by birth an hereditary member of the Democrat Aristocracy, Harris is ever but one gaff away from driving millions of loyal Democrats to pull the lever for Junior. If Harris can stay on topic and not embarrass herself and her party the net effect of RFK is favorable to the Democrats, if small. If one black swan appears in October, for instance a major terror attack in the United States, or China invades Taiwan, or Harris has a disastrous debate, RFK is a refuge for loyal Democrats who will never vote for a Republican.
I will try to be nice about this....
I have very low confidence in your analysis.
Lol.