I call shennanagins! No child is as creative as my dog.
My dog ocassionally does science exparements. And he's certainly more likely to randomly decide that the doorbell is an intruder and stampede through the home running in circles making the windows shake with his bark. For the record the 2 cats I have also see how high they can climb and one is 25 lbs. I also sit another 190 pound mastif, and two two year old (human) cousins.
My point is, human or beast can just as easily stab a stick... or lamp etc, through the grill of those in walls as they could a tower speaker. The other point is that if you are willing to spend a bit more on more speakers, take what you have back and just get a better pair of fronts. I can promise you that you will get better sound out of tower speakers than in wall speakers.*
If that doesn't work for you still though. If you can change the toe of the speakers try to adjust them untill you can hear a difference. What is lacking from your current experience?
*DIY and custom designs such as custom/active crossovers excluded.