The original discussion was this:
Your point about TFW splitting West Wales - Manchester services was nothing to do with train crew training, it was due to the introduction of Mk4's. It was also nothing to do with 197's as they run through to West Wales. 175/15x were running on West Wales - Manchester services during the changeover. So nothing to do with the topic we're referring to of Cardiff - Penzance for GWR. You seem to want to drop TFW's decision about Mk4's into every possible topic.
If GWR have the setup to train crews at both ends of the route then there shouldn't be any need to split the routes. It depends how quick they want to get them into service.
I understand your desire to defend TfW, that's fine as presumably your use of the line was not impacted as badly as those of us who travel from West Wales to Manchester.
But since this is about splitting a direct service (do we agree on that?) and TfW split a direct service (we presumably agree on that) then it does follow that what I said is entirely relevant. In response to those saying that direct services should not be split, I gave an example where one was split and where the split was not for a logical reason (like speeding up introduction of new services), but purely to get rolling stock into use that actually is not suitable for the job (because the 68s cannot run the full diagram).
I challenge you to find a single case I have mentioned TfW splitting Manchester to West Wales on anything other than the Mk4 thread, the 197 thread, the previous threads about withdrawing 175s (All directly relevant), a thread about terminating trains in Cardiff (there have been a few about the impact of terminating trains in Cardiff on GWR services as well as the station design at Cardiff), or a thread about splitting direct services. I am sure there are none because I do not drop TfWs vanity project into "every possible topic".
If you still want to discuss TfW then maybe we should take it back to the thread on the Mk4s and leave this here as it is, an example of a split service with no intention to restore later.
In this case, I think allowing the 175s to be introduced on the Penzance services sooner, with the benefit that IETs can go back to helping where they were originally booked to be.
It is not just the IETs, there is the shortage of 158s too.
The 158s keep being borrowed from Cardiff-Portsmouth leaving 2car trains.
As example todays 1F12 Portsmouth-Cardiff lost 15 mins by Bath, following train 1F14 lost 10 mins by Bath.
Return CDF-PMH 1F15 also lost 10 mins by Bath, and according to real time trains took 4.5 minutes at Bath which shows how slow churn is when reduced to 2car 158s
IF splitting the Penzance to Cardiff to get 175s in quicker helps with the 158s then that is a noble cause too.
Having the chance to bring more units into use quicker has to be worth some temporary pain in terms of connections in what used to be direct services.