Continental Saxon religion is known almost entirely from the documents of its suppression. The Frankish annals record that Charlemagne destroyed the Irminsul in 772, a great wooden pillar the Saxons are said to have venerated, and the surviving lists of prohibited practices, drawn up for the use of missionaries, name what was to be stopped: offerings at springs, at trees and at stones, the burning of the dead, divination by lots, and the eating of sacrificial food.
The abjuration formula preserved for Saxon converts requires the renunciation of Thunaer, Woden and Saxnot by name, which is the clearest evidence for the pantheon and is also the only context in which the last of those names appears at all. David Wilson's study of the paganism of the related Anglo-Saxon settlers works from the same kind of material and shows how little can be built on it without importing Norse evidence, which belongs to a different branch and a later date.
The atlas therefore records the Saxon gods as attested by name, records the practices as attested by prohibition, and marks the rest as unrecoverable rather than filling the gap from Scandinavia. What a Saxon believed about any of it is not in the record, because nobody who held the religion wrote anything down.