I agree too, but I think this kind of problems should be solved in a more general way.
Proposition 1: All games that can be started automatically, should start automatically.
This means that a new tournament round should be started as soon the winners from the previous round are identified. And when next game in a siege can be started it should also be started.
Proposition 2: Time out the inactive games automatically
Let no game be able to stall due to inactivity. If the time is out and the opponent doesn't move then he should lose the game and the tournament, siege or whatever should go on. I both players are inactive then the one with the move should lose the game.
Even if there will be a lot of null-games, the tournaments or sieges still progresses, and that is what we want. It's not enough to be able to click the skull; if no one clicks the skull then the siege is stalled and stuck.
So automatic game starts and automatic time outs is the solution out more than siege problems...