what will happen if you build a 4 port USB hub without the hub controller in it. (i.e. The ports are in parallel)?

i am wandering if the USB host stack can enumerate the devices connected to that peripheral

USB, or Universal Serial Bus, is a serial device; this means there is only one data line used for transmission.  If more than one device tries to talk at once, it creates digital gibberish on the data line.  You have to have an intelligent controller in order to sort things out.
No, it won't work, there will be a massive contention issue on the bus. The whole point of a hub controller is it stops that happening.