M&B combat, while being far, far better and more immersive than most gaming combat out there, is still a comedy of unrealism compared to "real life" combat. The lack of depth and mechanical limitations dictate that spam, while being hardly criticized and fought against, is the only manner of winning.
Otherwise, there are so many variables in combat that are not in the game: a man can thrust while simultaneously blocking an attack in the right stance, and believe it or not the whole Roman military revolved around the "hide behind board and poke" strategy. Simplistic, but effective, and terribly easy to learn.
Another aspect is speed: earlier beta patches had great axes have the same speed as fighting picks. This is absurd and unrealistic - then there's the "downward, side slash" of spears, which is also ridiculously fast and ironically better than their horizontal combat actions like thrusting.
All of this just serves to show that M&B combat is more like a category in itself and not a loyal reflexion of "realistic" combat. Some modules try to address this, like RCM, but the result is that two handers get pretty useless mean time; while the historical and realistic value of this approach is hardly debatable, since the vast majority of melee fighters up to the age of plate preferred weapon and shield combos, it is bound to raise the eyebrows of players who must sense an underlying utility and advantage to *every* weapon.
In my opinion, save for really fast swingers like katanas and bastard swords (both otherwise very pathetic versus any decent heavy armour), 2-hander behemoths should be mere specialist weaponry. The vast majority of all melee fighters must necessarily carry weapon and shield combo.
And on another historical note, Scots did not carry claymores; that's a myth. Most (high status) Scots fought pretty much like their English neighbors and used 1-hander sword and shield.