Your daughter is a very smart girl. I would have done the exact same thing if I were her.
In fact, I am seriously considering doing the same. Only one problem, I don’t have any low level troops anymore. But on monday I’ll be getting the GW reward troop, so I can just set 4 of those at level 1 as my PVP defense. So that should give me varied PVP choices again.
Or, and I’m just asking the exploit police this in advance: Would that be “against the spirit of the game” again? 
(can’t find the rolleyes smiley, sorry…)
Because let’s face facts: The Elspeth “fix” fixed a symptom, not the problem. I understand that fixing the problem is infinitely harder than fixing the real problem (boring, unvaried endgame meta), but still this “solution” is rather disappointing…