They certainly did their research.
Also, Middle Ages was a long period of time and things worked differently depending on where on Europe you were located.
You can't just say "on average" and disregard context.
I don't doubt they did their research, but they also failed in many aspects to achieve the historical accuracy they touted.
And no, there were no times during medieval Europe, where a whole kingdom just decided to marry at 15 years old.
People marrying at 15 were the exception, not the rule, unlike the statement made by that dev.
Yeah that nonsense you quoted really grates on my nerves. Warhorse spent years researching the period to make this game, hired inhouse historian, and consulted with the absolute top czech historians specializing in the era. In the end, they were still making a game and not reality simulator, but they came as close as one can reasonably come under limitations of videogame medium and budget/time.
Just because you really like a game, doesn't mean others can't point out the flaws in it.
And when it comes to character writing, Henry is very poorly written for the context of the game.
Another confirmation of Henry's age
As for Henry's "lack of skills". It is a god damn point made in the game that neither his dad nor his mom want him to be a warrior. And he helps his dad with blacksmithing, right in the opening quest, so obviously he is learning the trade. And yes, he is a somewhat lazy layabout. That's also a point in the game. How he goes from a peasant to almost a knight through the events he gets into.
One thing is not wanting to become a professional warrior, another very different thing is not to be able to defend yourself and your town.
There are still registered accounts of people getting arrested and/or fined, during medieval times, for not owning a sword and to not rain to help protect the town. In other places it was the use of a bow. And in others, a polearm.
At 17-20 any abled men would have be proficient in the use of a weapon, by law.
And it's not just a matter of law, anyone who would travel between towns would have to know how to defend himself, or risk becoming killed by criminal or by wolfs.
In the game he does almost nothing related to blacksmithing. He just goes around doing mere errands.
If the game was realistic, at that new range of age, he would already be a decent blacksmith. In fact, at 20 he would probably be very close to being a master.
Henry, being the son of a master blacksmith would be trained from a young age. And he would probably have a couple of other apprentices, whose parents would pay to have their sons learn such skills.
Also consider that a blacksmith is not a peasant. Another telltale that you have little knowledge about the period.
A blacksmith is a highly skilled worker for the time, and considering that his father is doing high quality swords for a Lord, it means he is in the top of all the blacksmith class.
This means that in a much higher social strata than a peasant. In fact, he would have above him only the king, nobility, clergy and some bourgeoise.