– he judge it hard for a group of orphans to survive in the outside world, so he stayed under the protection of the griffon and teach the children the necessary skills to become self-sufficient (this is not hypocrisy, but rather simple humane charity, like how you would donate money) meanwhile helping himself to survive too (building close relations to others as a mental relief and working together to suffice physical needs)
-he accepted Tetra despite himself doesn’t have romantic feelings to her. To be honest, where in the world would there really be a couple who are mutually in love with each other before they started dating? In extremely rare conditions, yes? Further more, by the time of the story, the MC is already around 30 by mental age, would he really be capable of fierce romantic relationships? Thats why later on, when the princess fall in love with him (with enough reasons: 1. First friend and a long time friend, which means he is an important figure in her life, 2. He’s is strong, which is a major criteria in choosing mate in classical eras), he will accept her as 1. He doesn’t really has loyalty bound to Tetra as he is not romantically invested, 2. The world he lives in supports polygamy, there is no moral values restricting him. He wouldn’t really have a reason to reject the offer, didn’t he?
-after the first war as a king, he purged those of the opposite factions without mercy after them not swearing their allegiance. As a king of a country, for the responsibility to prevent any civil wars from happening and for his own interests (the safety of himself and his family), his merciless act can only be judged as a logical yet unethical way.
-And under a necessary amount of ‘luck’- which is him meeting influential people, getting some strong yet not op skills, and finding good opportunities- he succeeded in becoming a great king and eventually the founding father of an empire. This is not “plot armor” but rather what makes some of the rl great people in our history great — opportunities, relationships, and skills. When all of these things align together well, it made the legend of roman empire feasible. Although the chances of them aligning perfectly is rare, but it is only natural for a “story” to be depicting such rare occasion.