Find the biggest defense in your realm (might have to get them to all rein one person, to make it higher) and send just a march of your T2’s against their wall. Make sure to only send one dragon, and make it your weakest one. Presuming you can get your attack to be 0.01% of the wall you are hitting you should be able to kill all the T2 in one hit.
I think the solution would be the ability to train them to the next level. Possibly at a percentage loss, due to “untrainable” or “dropouts”. i.e. out of 100,000 troop only 75,000 “graduate” to the next level. It would require the training slots (a little less time/resources then training from scratch)
If you attack is 10,000% less than the wall you are attacking, 100% of your march will die. In other words, find a player with a 100b wall. Send an attack with your weakest 1 dragon and only enough troops to have less than 10m power. All of the troops in that march will die. Makes getting rid of weaker troops a lot easier. Either that or let someone fill your hospital with good troops. After that you can lose dang near entire marches by attacking a higher wall.