Hello there, i have played my first generation as a shielder/throw, then i played 8 gens as a dedicatand 2h and now this gen i am playing pure 1h/shield.
As a former dedicated 2h now shielder all i can say to this topic is: l2p
Now this may offend you wich was not my intention, it may sound elitist wich was also not my intention, so let me elaborate:
Let say two players are roughly the same lvl. One is a 2h, the other is a shielder. No matter how fast the 2h swings if the shielder swings after his shield was struck the 2h will have to block or die, he cannot outspam you.
Now you will probably think: What the hell is this guy talking about, i was outspammed countless times even when i did that.
Now let me tell you why:
Superior footwork - mostly happens when you are trying to face hug an enemy, instead of fleeing he dances around you spamming and hits you on the sides or on the back
Range - outranges you with his weapon, this is also footwork, jump backwards slash while you try to retaliate and such
Bad reaction time - You waited too long with your swing after the block
Bad fient time - Fient after block against a spammer is a no-no, just atack him
The speed of the 2h-s weapon and the ammount of his agility is irelevant. If you use smart footwork and listen to your shield (yes listen, hear the sound of the block, let it be your "atack now!" sound) no matter how fast he is he cannot outspam you. Also turn up your mouse sensitivity so you can keep track with the guys that will try to circle around you.