Battlefield 3 is a good example.
When using a mortar in BF3 your minimap is given a cross-hair to aim with when raining explosives down on your enemies. The player’s camera would move according to where they are aiming with the minimap help.
No reason it wouldn’t be fair. It gives the player to ability to use full range and anyone can use it, ally or foe.
Players already glitch or hack to get better arrow cart shots in WvW. This would give everyone a fair chance.