If holding an item by itself makes you multigrasp it, you're going to have a penalty in both accuracy and power if you try to wield it with one hand.
Dual wielding is only a good choice if both weapons can be used one-handed without penalty, and even then it generally inferior to one-handed weapon+shield.
Which is inferior to 10x weapons and 10x shields, but I consider that an exploit and don't use it.
I usually limit myself to only 1 1-handed item per hand, or a 2-handed weapon and a buckler. It just seems more realistic to use a smaller shield with my big sword.
As far as I know, even using just a buckler takes up full use of that hand, so you're still getting penalties (though some adventurers are big/strong enough to wield normally 2-handed weapons with one).