This is a fine House Rule, and simpler than the one I proposed. If I ever have to deal with this cheese, I'd be tempted to use yours instead.
However, technically the two actions could not be simultaneous, per the RAW. A standard action takes longer than a move action. So what you're suggesting would look something like this.
Use wand......pass wand
------------>-------->
-------->------------>
get wand......use wand
Note where the "use wand" parts overlap in the center. That'd be where the two wizards were using the same wand
at the same time.
Still, for simplicity's sake, and to allow a bit of flexibility, I still like your House Rule.