In all honesty if you go somewhere to do something do you want someone saying “while you’re waiting we are going to do something completely different for no other reason than we don’t want you sitting around”. Which is all concurrent activities are. Don’t know about you but I’d ignore them or say no (or something like that).
I remember telling a member of Wing Staff I wasn’t 5 and didn’t need someone giving me something to do all the time and promptly went back to my crossword.
Then you give them the option to join in or not, if they’re bored they will have a go at a fun activity.
Make it more shooting related, teach them a skill they might not have yet, get a harmonising target out and get them calling out GRIT commands, get some paintball gear and run a paintball range on some suitable land.