The term "Tribal Hidage" may perhaps have led scholars to underestimate how the names of the tribes were used by Anglo-Saxon administrators for the purpose of labelling local regions; the names could be referring to actual peoples (whose identity was retained after they fell under Mercian domination), or administrative areas that were unconnected with the names of local peoples. Campbell suggests that the truth lies somewhere between these two possibilities. Davies and Vierck believe the smallest of the groups in the Tribal Hidage originated from populations formed into tribes after the departure of the Romans in the fifth century and suggest that these tribes might sometimes have joined forces, until large kingdoms such as Mercia emerged around the beginning of the 7th century. Scott DeGregorio has argued that the Tribal Hidage provides evidence that Anglo-Saxon governments required a system of "detailed assessment" in order to construct great earthworks such as Offa's Dyke.