There are plenty of clans padding the bottom with low level THs in an attempt to have the top bases face weaker opponents. Nothing is foolproof in MM, but it seems to work enough that people keep doing it.
A lot of clans running engineered accounts seem to have them because of some poor attackers in the clan. We've beaten some engineers that had lousy players, but engineered clans were a disproportionate share of our losses from April through September. It's been a lot better since the update. We are on a 10 war win streak, though we are currently facing what looks like a decent clan running 2 well thought out engineered accounts that will give them a slight cushion for bad attacks. They also threw a TH4 at the bottom of what's otherwise TH8 - TH9.5.



