I’m not a Chrysler guy and have no idea what the book time on a rear strut replacement is on these particular cars, but the average time on most strut replacements is around an hour and a half per strut; so, 3 hours to possibly 4 X the shop flat rate labor charge.
Keep in mind there is no law or anything else that says a shop must abide by the labor guide. The book is exactly that - a guide, and is exactly like a car value guide such as KBB or Edmunds. It’s guidelines only.
It will state in the front of these labor guides the same thing and that extra time should be alloted and charged for any unforseen things that crop up such as frozen bolts or other things that are no fault of the shops.
Even then, a shop is under no obligation to go by the book anyway although a reputable shop should stay in the same neighborhood time wise or risk pricing themselves out of business.
JMHO anyway and hope it helps.