Tower damage in this game is badly implemented. In the first 5 levels towers rape face rediculously hard, and after level 7 - 10 players are walking through lanes unhindered by 4 + towers hitting them. It's not as if taking a tower down is difficult, so tower position and damage output should be a large part of the game through all 20 levels and some. This is easily corrected by giving towers % based damage on DG.
Here is the current situation, towers hit for about 300 and we mitigate enough to take it to 250 - 150. At level 10, with 5 k HP and 40 % mitigation running into 4 towers for 20 seconds is survivable. This means safety is not on your line of towers anymore. This really hinders gameplay in the fact that the already 'winning' team gets rewarded by being able to hunt down weaker players inside of there base.
Towers should be % based damage, so they scale throughout the game. This would create more innitiative to take down towers faster, and benefit defending your towers much more than defending them means now. Letting 2 - 4 towers fall is currently not a big deal, but when towers are actually useful it becomes important to keep them alive. Lets say a 10% mitigatable damage from towers was implemented. This means literally, 10 hits from a tower to a low armored DG will kill them. If a DG is well geared in armor, it will take about 20 hits. In a situation as above with 4 towers hitting this buff DG, his survivability would only be around 5 seconds, and never more than double the survivability of the 'loosing' or 'poorly equiped' team.
This helps keep a safety line closer to the battle front for both sides. It helps even the playing field regardless of who has the edge, and will increase the playability of the game as well as reduce rage quiting due to dying from being chased into your citadel at level 10 and still dying.
Some other changes that must be made to towers, is that they target DG. Always target DG if they are within range. This means minion builds either attack with just minions, or better be prepared to take the heat from a tower they are attacking. It also gives a great benefit to classes that have effective stuns to towers, such as ICE TB and Tower Sucking Rook. It also will reduce early game destruction of towers from keeping players from using towers / grunts to soak damage while they pelt the towers. Regulus auto attack is still an issue, but when your viable tower hunters becomes minion builds, tower hunting rook, ice TB, siege QoT and regulus, it is much better than the current state where any DG can kill towers without much fear.
Small changes like this are not only easily implementable, they will change the game in a beneficial way for future players. It will also add new elements of game play for the more seasoned players, and create a more challenging environment than the current play field.