The timetables are not available on the website anymore.
https://tfw.wales/draft-timetables-2023 returns access denied.
I would disagree with this view. Cardiff Central tracks are very poorly suited to any kind of terminating trains either incoming from the west or the east. The layout is such that to attain any stabling position or turning point and then coming back on the platform, trains have to cross the mainline therefore creating both a pathing constraint and a reliability hazard. I was worried about the 2022 timetable due to the fact that it increased the number of Cardiff terminators substantially.
Secondly, Cardiff is not a nice station to change at, it is busy and your trains are not always leaving from the convenient platform (e.g. use of the 0 platform Eastbound and couple trains leaving from 3/4 Eastbound). Loads of stairs and a connection time that cannot be brought under 5 minutes. I would argue that in spite of its location Swansea has the benefit of providing a level floor nearly fully covered. Connection times could be around the 5 minutes. It also has lower level of traffic limiting pathing conflicts out of the station and is a natural terminus for traffic coming from the West.
Hence operationally, even if there is less than a Mk4 set every 2hours, pushing further west to Swansea could be easier to deal with.
As for the pathing of westbound trains the problem is the Maesteg branch it also represents a major reliability hazard in everyday trafic and a huge pathing constraint. The second hourly GWR train in the evening is domesticated west of Cardiff. There are not many ways to improve it. The easiest way to dispense with it would be to run shuttles but that won't be easy to accept. In turn another swanline type service would have more flexibility to deal with this if it leaves behind the GWR service.