No need to worry that a Fortuner will lose in value, just because a new model has been released. The new model was launched with a price hike, so getting the old one will result in significant savings.
Design wise the new model is more evolution than revolution. So its not like the old Fortuner will look or feel old, just because the new one excist.
Most important of all there is demand for Fortuners because of Toyotas reputation for reliability and durability. And a new model does not change that reputation.
A budget of 1,2M is overkill also. As a repo car Fortuners now trade for somewhere between 900k and 1,05M, unless you want the 4x4 model, which is difficult to find.
Monteros are a bit cheaper, which reflect that they were also cheaper when new. The Trailblazer is difficult to find as a repo car, and long term maintenence costs are uncertain, because its an unproved brand, which is new to the market. It is for sure not as safe a choise as the other two.
The Santa Fe is a really nice vehicle, but its something very different from the pick-up based SUV´s. More comfortable and refined but less durable if used on unpaved rural roads.
It uses a monocoque platform, so despite the diesel engines, its real competitors are the RAV4, Honda CR-V and Nissan X-trail, and not the Fortuner, Montero etc.
Personally I would be highly tempted to get the Santa Fe, but like the Trailblazer it is not so easy to find as a repo car. Its sister car the Kia Sorento seem to be a much more frequent visitor at repo warehouses.