There's a difference for sure, maybe not bringing memory to a crash but more likely stressing CPU usage, at the server and locally.
There's one player in each situation who has control over the avatar, selecting the variables of the stroke and performing the stroke. That's about it in single mode.
In two player mode, add another display of the situation, the options and the shot, and add the chat between them.
Add this once more for each additional player.
Thus it seems logical that the situation is more delicate, locally and in the net between the players, and more vulnerable.