So, we all know what's going to happen in the mid season. Tanks will now have 10k+ health (ironically speaking), will still some continuous damage and not to mention bruisers/fighters that will solo carry through your base hard rocking. To "counter" that I thought that the solution to this problem was in fact quiet "simple". Reduce their movement speed by each tank item they have. For example: Sunfire cape has -3% movement speed, apart from all those stats that it'll have.
After all that's what tanks are: Slow, but can take a lot.