Montana is based on the B-segment platform like Fiat Strada and VW Saveiro, whereas Maverick, Santa Cruz, and Fiat Toro are C-segment size.The old Chevy Tornado/Montano is a coupe' utility, so it's a different class. It's also tiny, slow, and very cheaply made (interior materials) to meet the demands of it's intended market.
That spy photo above though.. does seem like they are making it more US market friendly with the quad cab. Kind of changes it's cheap regular cab work truck market target.
The old Montana was a 2 door because that's what the market used to demand but since Fiat Strada came out, it's obvious that the market demands for B-segment truck is trending towards 4 door as well.
The new Montana is basically truck version of Chevy Tracker (Trax) that we don't get in the US.