Next dark troop lvl up idea

The way the troops lvl up now is great but for some ppl it can be a pain. I believe a good alternative to this problem would be for the troops to earn xp over time from the completion on many tasks. The most general one would be use the troop "x" amount of time in a battle. Now there will be more ways than this to earn xp but this is just one of the more common task. This won't go for all troops just certain ones of your choosing. For example, the new dark troop, which is yet to be revealed, would need to be used 150 desperate times in order to earn 150 xp. The troop would require 250-500 or whatever number works best for you. The leveling up would work the same as it does now, increases health, damage, and cost of the troop. This could make a big impact on the game as it would satisfy many of the players.
As an example, you could make it so u have to spend gems to make the troop upgradeable. Now this would require a building. Thus building would be called "lab-x". This looks similar to the laboratory troop upgrade now. It will also take time to unlock the troop for xp upgrading, such as the laboratory does now. Although, instead of using elixier for upgrades, it would use gems. Now when the upgrade is finished, the troop will have a green symbol similar to the troop lvl symbol, in the bottom right corner of its picture. This means that it is available for the xp upgrading. And, as stated before, the troop will be required to earn the xp in quests. I hope this gets added to the game as this would make a lot of players happy.