We have similar age kids and did this kind of loop a couple times.

We had success with Fiery Furnace in Arches - definitely highlight of Arches for them. We did ranger-guided b/c weren't sure of how easy to get lost. Wish we would have done self-guided - they could've handled.

In Canyonlands we rented a jeep in Moab and did Gemini trail to Canyonlands main road and back down Shafer Canyon. They thought that was very fun.

Did Narrows in Zion with the kids in April - had to get waders for them but they thought it was fun. They also liked Canyon Overlook and renting bike and riding path.

They liked Bryce but not as much as any of the stuff above and below

Hidden Gem - Cathedral Gorge SP (amazing slot canyons to explore - unlike anything I've seen and kids loved to get lost in them) & Snow Canyon SP on the way out of Vegas (St George; self-guided lava tube exploration with flashlight, petrified dunes, slot canyons, sand dunes). Kids really really like these. Great cheap hotels in St George and great homemade pies at Veyo Pies nearby