You are not obligated to carry an overly long one-handed weapon.
What you've got to do is adjust your playstyle based upon the length of the weapon you decide to use. If you're a shielder in heavy armour, you aren't going to be chasing anyone with more than 6 athletics down. If they relentlessly press their S-key, have the presence of mind to just WALK THE FUCK AWAY. If you're using a long weapon, sometimes you can catch a moderately (at best) damaging blow to them, but often they'll still just be a pure headache to fight. You're going to give yourself a much harder time than is needed by chasing people that want to run away from you. Fight with your teammates, try to block them from ranged and if they get knocked down or ganged up on. It's always very nice to put your shield in-between a disadvantaged teammate and danger.
But for god's sake, don't get in the way of someone dueling or a situation in which your guys already have the advantage. And whatever you do, don't stand directly behind any melee players holding your shield up. It'll prevent them from overheading and get them fucked.