Greenfield (Flex metal) is also a possibility
Legally raceway systems are supposed to be installed empty, then you pull the wire. I am not saying I have never seen feed as you go but it isn't legal and it was on the line side of the service point so I didn't have a say in it. (service laterals run by the FPL contractor). OTOH I would really like to see someone pull wire through a carflex elbow at anywhere near the conduit limit.
It is always easier to pull than push, particularly any raceway with ridges inside like FMC but it does give you a lot of flexibility in the installation. Is the OP in Chicago? That is one of the few places that don't like non-metallic wiring methods. Using EMT as the ground is legal but these days most inspectors want compression connectors made up wrench tight. Flex generally can't be used as the ground. The exception is AC cable but that has a bonding strip inside. There is also an MC cable that uses a thick aluminum bonding conductor inside. The intent is to eliminate the "choke" effect of that coiled armor.