I think the DXIRE is just the lower end varaint name for City.
The top end version being "ASPIRE"
The lower end 1.2 litre with a new name "DXIRE".
NO two models like Amaze and City. Just the one City.
As of engine, the 1.3L was also not available on the 5th generation City as we have as of now but as it shares platform with FIT / Jazz, and that had 1.3, we saw it on the our City.
Same might be the case with with GM6 City. 1.2L is available on FIT and GM6 and 3rd gen FIT are technically related so, its availability on GM6 is possible