I disagree with this. not only are the combat techniques different, but the various armor styles can lessen or defeat blade or blunt weapons. Chainmail can stop a blade, but does almost nothing against a mace. :shrug:
Everything is different on some level in real life, but it is also unrealistic to be a master of long swords and than suddenly be useless with a blunt weapon, a lot of the skill lies with balance and body, and reading the opponent, the fact that various armor types can yield different results with different weapons, is okay, but that is a property of the armor, not a skill.
As for game mechanics: Have you not played an RPG where your PC must resort to an unfamiliar weapon, and do so at a severe loss of attack skill? A combined skill means that every fighter in that world is equally skilled in bladed and blunt... This means from one skill they receive equal proficiency in foils, daggers and warhammers.
I consider this terribly unrealistic, and creatively limiting to character design.
Yes but if the weapons aren't very different, say both are 1handed, than it is equally unrealistic that someone would forget combat training, completely, simply because the end of the weapon is blunt. There's a larger difference between a mace and a staff, than a mace and a sword, even though the mace and the staff, both are blunt weapons.
In any case, in Skyrim they have said that the majority of the power lies with the perks, so even though two people have a high 1handed skill, they can have enough specialization inside the skill in different weapons to get a noticeable advantage/disadvantage difference, so the player is better off sticking to the specific weapon type of advantage.