Generally, the bigger the lugs (tread blocks) the more likely a tire is to "cup". Yes, you absolutely should check ALL steering components often. What is the air pressure in your tires ? Do you check it (chalk check ) every pre-trip and load / temperature change ? This is ABSOLUTELY the number ONE cause of tire wear issues. How do you use the truck ? On the street with lots of turning ? Turning will eat up the edges of these kinds of tires rather quickly even with perfectly set (which NEVER happens) toe-in. If most of your driving is straight line with minimal turns, then it could be a setting or component problem. Are your king pins and bushings in good shape ( no perceptible movement when "yooksed" in and out at the top and bottom ) or you can get out your dial indicator and check them correctly ( ummmmmmm, nah . . . unless I am setting them up the first time ) If the wear is exactly the same on both sides you can try changing the toe-in. Somewhere between .3 degrees and whatever the spec is ( field check -- measure with a string across the inner edges of the wheels, if front measurement is just slightly less (1/4 to 1/2 an inch, 7 to 13 mm for you metric fans) than the rear, yer in the soccer stadium. When I off-roaded a lot I kept a string with markings on it in my toolbox. Makes spotting bent parts a LOT easier. Speaking of bent ( like my mind ) is your tie - rod straight ? Are ya sure ? A little won't matter but if it is, or worse, was and was pushed back to "straight" it might actually be "changing, as in flexing" under load. If that is going on, VERRRRRY DANGEROUS. It WILL snap, and always at the worst time ( in the middle of a turn after hitting the bump just before it. ) Not something I want happening while I'm driving a B A T down the high-way. No cure for that except replacement.
Also, tire rotation, if all the tires are the same, will extend the life of the tires but, obviously, won't fix the cause of the wear. Don't hide "bad" parts by keeping the tires rotated.
Edit - just saw Wes' - yeah, worn dampeners (shocks) will also cause wear. This is usually found on one side at a time unless a weird change in "the force" makes them both go at the same time.
so, make sure everything is clean, tight, and right, then blame Michelin. The French should stick to food. (love yuz frogs ! and all our canuck neighbors to the north, too)
Good luck and Happy Motoring !
