A better idea than to have a drag-bag is to outfit each person in your party with their own hands-free bag on their back.
A bag that is dragged simultaneously removes one or more hands from being useful while also restricting movement greatly. Furthermore, as mentioned previously, the wheels are worthless on soft or uneven ground and will usually contribute to "tip-over" of the luggage and require greater energy/time expenditure to right it and continue mission.
With a worn bag you will have the benefits of less exertion, particularly if the bag is worn correctly, i.e. very high and tight upon your person. If you anticipate or encounter fire then you can easily ditch the bag and get to business and recover the bag when safe. A "normal" bookbag doesn't have reliable zippers nor quick-release straps and buckles, but "military-grade" bags do.
For us, we have:
BugOutBag, Bug Out Gear: One black and one ACU
MOLLE Assault Pack, US Army, RFI
With each person utilizing a backpack you can disperse supplies so that each person has redundant items. Spare flashlights, batteries, food, water, medkits, knives, et al. in every bag in case one is lost. As was stated earlier, using a huge rollerbag means you will put all your eggs in one basket and if it gets lost you're out a lot more than if you lost a backpack with items that are duplicated in one or two other identical bags.
Bottom line is that a roller bag is going to inhibit movement and hinder tactical response.