So unless I'm mis-understanding, the Defenders will wear better than the MXVs which will wear better than the Ecopia's (at this point I would believe that just about ANYTHING will wear better than the Ecopia's
). In other words, the Michelin Defenders aren't a bad choice?
All tires strike a compromise between treadwear, traction, handling, and other variables... So it really depends on what you're looking for and what you're willing to accept. The Defender's ratings seem perfectly reasonable for a passenger tire if you're looking for maximum tread life; not every vehicle is or needs to be a sports car. Some people are just fine with Taxi, or Limo.
I just bought a set of new Ecopias for my wife's Subaru. She was most interested in fuel efficiency. The tires other attributes aren't necessarily optimal but they're just fine for what her car is going to be used for. Again, it's all about what attributes are most important to YOU.
To be fair, the UTQG ratings say nothing about handling. They define "traction" as a function of straight-line wet braking.
For more details, check out tests and customer reviews and compare different tires, for example at tirerack.com.