To be competitive to the new Tahoe/Yukon it should be adopting IRS, it makes much more room for third row seating and cargo and Toyota is the vehicle selling business and this is a huge segment of the market they have missed for years.
Some thoughts,
I think the the Tahoe/Yukon are sell significantly more units in the US for a few reasons.
Shorter development cycles, Americans love new stuff, From 1000 dollar smart phones to eating tens of thousands of dollars in depreciation on new vehicles, Americans just love trading in perfectly serviceable stuff for the latest edition with blue tooth 3.0, wireless charging, a display that's an inch or two large or any other number of gimmicks.
While I personally appreciate Toyotas approach to reliability, since the last significant change to the Tundra/Sequioa in 2008, GM is now on their 3rd generation of of the platform even before toyota can launch their next gen platform, Bottom line, people are blowing 70k on a vehicle with a decade old tech package
In regards to the cargo, third row seating, We have new Yukons as work vehicles and honestly, they have never had usable 3rd row seating for adults. They are great for 4 adults with a decent amount of gear, but anything more and they suck.
If Toyota wants to compete in the large SUV and Truck market, they need to either have shorter development cycles, or do something that the big three do not. I think the one area in which they do have the ability to sell really well is if they basically approach the segment as if was the 4 runner. The 4 runner is successful because it can complete against Jeep as well doing outdoor stuff and offers more storage space.
The should market it is a larger 4 runner/tacoma, Americans love the idea of outdoor adventures, and can be sold quite easily on the concept,