To be quite honest, I think Adarshan Hanayome is not a manga focused purely on romance only. Even if the main point of the story (up until now that is) is the marriage between a man and a girl with an age gap that many find unsettling.
I think the main point of the story is the focus on the kingdoms of that medieval world setting, especially Castoria and its monarchy. I'm getting the feeling the mangaka would later move the attention to it on future chapters. It's a bit like Kyou Kara Maou, you expect some fluffy BL moments but most of the time, the story revolves around the Demon Tribe and how Yuri handles his duties as the king.
I'm guessing Adarshan would be the same way, most of the story revolves around Alexid instead as he performs his duties for his brother, the king and the politics of the country. The romance is just there, as part of the plot, but it's not going to get mainstream anytime soon. Yes, there might be some mushy scenes between Alexid and Justinia later on but as evidenced on chapters 1-3, they're mostly platonic. Nothing really that romantic in a sense.
Still, I have high hopes for this manga, look at the gorgeous artwork. And it has tons of potential that hopefully won't get wasted.