Hi Mad Pup!
If there are not so many resistance units going around, you may try to give each one of them a name (es. res1, res2, res3, res4 etc.) and then, when you want them to stop doing anything, you may try to run this line:
{_x stop true} forEach [res1, res2, res3, res4]
Then, when you want resistance units to move again from where they previously left, you have to run this line:
{_x stop false} forEach [res1, res2, res3, res4]
Cheers!