Idea for item to help tanks out in team fights while keeping them balanced esle where.

Okay so I was thinking what could make tanks more tanky without causing a lot of other problems such as them being unkillable in lane or being the last man alive in team fights that just wins by beating everyone else to death with a wet noodle.

My idea is to introduce an item that gives % armor and magic resistance for every team mate the player has around them. The % magic and armor only gives the stats to the tank. This would allow the tank to absorb damage at the same time not allow him to just run everyone else over 1v1.

The item would look something like this

Example Item X health X armor X magic resistance Unique passive For every ally champion within X range you gain X% of your bonus Magic and Armor.

I think this would help make tanks less of a target you could jump (Thresh hooking or blitz grabbing the tank shouldn't be a good thing) on while still letting people 1v1 them when they don't have business doing it.