As far as the conflicts that develop when a team has multiple contenders for winning the Tour, the history over the last few years actually is not that bad, at least from the perspective of the team getting results. Setting aside the 2018 and 2019 Tours, in which Thomas/Froome and Bernal/Thomas managed to get podium spots with no apparent conflicts, and the Movistar situation, which I would argue is not particularly relevant, as the only Tour in which there was a Movistar rider who was able to contend for the win and in which there was a conflict would be 2015, and even that is quite possibly not a conflict as much as Quintana feeling a rider did not perform as well as hoped. Even with that, Quintana finished second at the Tour in 2015, which is not a particularly bad result, I would argue.
That leaves us with the Tours of 2012 and 2009, which both had definite conflicts inside teams. Both were ones where definite, specific damage was done to relationships between contenders for the win, and, yet, in both cases, the riders who were in conflict managed to end up with a win and a podium. There may well have been damage done to the long-term relationship of one of the riders with the team, and that is not nothing, but in both instances, the team made the choice to stay with the stronger rider, and were rewarded for doing so with another win (setting aside, of course, the Clinic issues that apply to 2009).
My point being that the road has always decided, whether there is conflict or not, and when there is conflict, its effects are trumped by results. The riders may not see it that way, and may feel betrayed by the team, and may be right in so doing, but from the team perspective, the results are the primary focus, and the means of evaluating what is important to the team.