Yeah, this is deliberate. It's very easy to play a typical dark ages warrior in most games (chain, axe, beard, done) and I wanted the Redwald PCs, to be different, true outsiders. Not part of Redwald's establishment. In some ways the standard dark age warrior is the setting's `Orc`.
Of course, that's just how I wanted things at my table. If you want to do things differently, or have a player that really, really want's to play an outlawed Thegn there's no reason not to change things up.
Re-skinning other warrior classes would be one way to go, the Sheildmaiden could be redone as an Aethling estranged from his family, or swap the dwarf's weapons for a sax and spear and make him a Fyrdman, or the Wildling Battlestrong could be re-skinned as a axe weilding Thegn, or even a Hearthweru.
The other way would be to look at the various Eordwerod bestiary entries and DIY a character class from one of those that is scaled to be comparable in power to the existing classes.