I agree with most of what you say but getting a second place in the Tour is a long way from winning it; especially when you've never won a prior GT. Vingegaard was opportunistic and well-supported with Roglic's absence. As for the two-fer strategy it didn't seem to work for Movistar and then they tried the three-fer. Ineos did the same.He was better in the TT and in the "cheap seconds stage". Again, he was better than Roglic then. He deservedly won the Tour. And it is the one who completes the entire Tour course in the shortest time anyway, who is the winner. Last year Roglic had bad luck and dropped out. But given Pogacar's demonstration, Roglic hadn't had a chance. And with the drop out of Roglic last year, we have now come to know Vingegaard as a potential Tour winner. During the preparatory races it will become clear whether Roglic or Vingegaard will be the leader of the team. Individually both will fall short against Pogacar.
My point is that by working together Vingegaard and Roglic can get Pogacar in trouble. I mean working together equally, without one of the two having to do slaves for the other. Take turns attacking. To put everything on the best placed team mate at the end of the Tour.
Cooperative work sounds good but when it happens it as much chance, resilient form or a one-off. Pogi does seem to be almost the best at everything which wins GTs. He also doesn't need a DS in his ear, a wattage meter or much support in the highest of mountains to accomplish it.