I'm not sure "it would be difficult to remove" outweighs the danger of "not having a shield ", if I'm honest. Shields were often strapped to the arm of the user, and tossing one aside was typically done only in rout or surrender, which is why mothers once told their sons to "come home with your shield or on it ".I would argue against Maedhros using a shield. While I agree that shields are extremely useful in battlefield combat, it might be impractical to have a shield attached to his arm that he could not remove efficiently without dropping or sheathing the sword in his other hand if he needed to do something that required the use of both arms.
True, dual wielding was much more common in individual combat, but soldiers often carried small blades, like the dagger or wakizashi, to use as a backup weapon, fighting in close quarters, or to finish off downed opponents. Maedhros' blade could be a small (5-10 in.) punching dagger with a bell guard that he could use to help parry or strike around shields or through chinks in helmets or armor. That would allow him to use his formerly dominant hand in a more active and versatile role than with a shield. Plus, it would look cooler to dramatically gesture with than a shield.
And while soldiers absolutely did carry daggers into combat, they are not nearly as effective at partying blows as shields are due to size, plus shields are pretty much the only way to parry arrow fire. (You could make the argument that an elf could do so with a blade if he or she saw it coming, but the battlefield is not a place where this is likely).
Shields did eventually fall out of common use with the advent of plate armor, because they became unnecessary. This freed up soldiers' off-hands to use holding longer piles, longer swords, so on. The rondel dagger became the weapon of choice for ending heavily armored opponents.
The effectiveness of shields in battle prior to the height of human armor manufacture cannot be overstated, and I think that making Maedhros a practical and effective warrior on the battlefield will look plenty cool.