If you think that ancient Anglo-Saxon and Scandinavian monarchies would be remotely suitable to the vastly different economic and cultural situation of today, I believe you and Tolkien are mistaken, as much as I admire Tolkien.
The "vastly different" cultural and economic climate you refer to is a result of the de-Christianization of Western society and its rejection of the natural law as a basis of human law. You are defending the very liberalism that has undercut Western civilization - a civilization predicated on the Christian (Catholic) religion and the institution of the Christian monarchy.
It's all a cycle tho, we are on the downside of Plato's anakyklosis of government. We will not return to monarchy until we return to the Truth.