This model is effectively the inverse of a normal fault reactivation or basin inversion setup, which would require direct extensional motion followed by oblique shortening to invert the existing normal faults. At least in the sandbox model world, both of these inversion approaches require oblique compression to produce thrust or reverse faults of sufficient steepness to match up with normal faults, whose dips are always steep in these models. A detail of the thrust inversion setup that may impact the slightly lower dip of the initial normal fault segment is the presence of the weak microbead decollement layer on the thrust ramp.