Full tank game (WIP)

Have you ever though of creating a team comp of nothing but tanks? Downsides Some of the downsides that i know of are that some tanks are not able to dish out much damage. While this may be true, some tanks can go with a hybrid or bruiser build, and still be tanky. Also, there are many things that the enemy team can do to counter a full tank team.
Upsides Some of the great upsides that the full tank game has is that it would make tower diving really easy considering that they'd do nothing to you. With enough hp your team can farm in the fountain. You wouldn't need minions to go into towers except for early game. How to do it First off, you will need champions that can be extremely tanky, and still deal dmg. Such as volibear, graves, and more. DO NOT have everyone on your team only build Health. You need armor, magic resist, and health regen. If your whole team only builds one of these things, the enemies can easily counter it. Example: If you were malphite with 1000 armor, not much could do anything to you, but if a enemy build some extreme armor penetration, your 1000 armor does nothing to save you. That is why there are more than just 2 ways to build tanky. That is why you need variation in the team.

Add suggestions and give advice. Looking for Team comps This is a work In Progress