Olivier
In modern F1, I can't see a train being successful, unless you have manipulation from both drivers within the team.
Why not? Suppose that the Mercs suffer extreme tyre degradation again; then their cars will be slower than the ones behind, and so will end up with a train behind them. It is highly likely that because of the degradation, unless the cars behind pit first, then when the Mercs pit, they will end up in traffic, who are almost certainly slower than the cars at the head of the queue... Hence Mercedes will lose time, and the cars who were behind the Mercs end up overtaking....
So what if the cars behind pit first? Well, then, there may be a case of an undercut, if they manage to find some clear track....
There are only 2 possibilities to pull off this strategy.
1. Be the first to pit of the queue, and come out in clean air.
2. Employ blocking tactics from the second driver to allow the first driver to get 25+ seconds down the road.....