I'm not sure you want to be connecting it that way.
Take RGBS from the arcade PCB and connect to the THS7374 inputs. Then connect the RGBS outputs of the THS7374 to the RGBS inputs of the CXA2075.
The CXA2075 does the RGBS to composite video / s-video conversion. The CXA2075 has output pins for composite video, chroma and luma.
You'll also need to supply the CXA2075 with an external clock, via a passive crystal and build your own oscillator circuit or via an active crystal oscillator. The value of crystal depends on whether you want NTSC or PAL output.
The CXA will need to be configured for NTSC or PAL output.
You also need to build an external trap filter for the CXA2075 or utilise the built in filter.
Aside from all the above, you need to provide power to both chips and use the appropriate decoupling capacitors. Additionally, some passive components are required on the video input / output lines for AC coupling and impedance matching.
Everything you need to know is in the datasheets.
You'll also want to attenuate the RGBS outputs if utilising an RGB monitor.
Lastly, don't forget that audio needs to be converted from speaker level to line level.