Hey guys,
Like a lot of similar multiplayer games, there's a bit of a "smurf" problem in Total War: Arena. And while most games require a person to make a smurf account in order to play with lower tiers, this is not necessary for Arena. In fact, the game itself seems to give incentives for this kind of behaviour. Everyone will go back from Tier X at some point to start ranking up the next part of the unit tree, and that's perfectly okay.
But right now Arena gives a huge advantage to these players, because their leaders will retain all of their upgrades. That means that you can find a leader with a fully upgraded ability tree fighting with tier I units. While their units are of the same tier as their opponents', they have a huge advantage because their fully ranked up abilities will buff their units to perform on a much higher level.
To solve this, I propose that when upgraded leaders fight with lower tier units, their abilities are restricted to the tier they are playing in. For instance, take a fully upgraded Leonidas, who decides to play tier II so he can rank up some of the units he hasn't tried yet. While he has all three abilities unlocked and upgraded to tier X, he should be limited to using the abilities available on tier II (and only upgraded to the extent tier II allows). This makes sure that this veteran player, who already has a huge advantage in this lower tier by virtue of his experience, does not get an even bigger advantage over the newer players more commonly found at the lower tiers.