5 vice 10 has been regular since the new trains started - it has improved, but is not exactly rare (1733 Padd-Weston is so formed as I write).
You persist with this "all is wonderful, nothing to see here" routine, despite all the evidence to the contrary. It's all very well Hitachi having delivered 34 of the 36 800/0s, but they should have done that back in February (8 months late and counting) and they should have delivered the last 800/3 in July (3 months late and counting).
Your post neatly illustrates what I was saying - one formation is short-formed and is immediately pounced on as proof of some huge issue still affecting multiple services all day, every day. A state of affairs that could indeed be described as routine, or regular.
But that's not what's happening now. You grudgingly concede there has been some improvement. I'd call the odd short-form a distinct improvement on days when there were multiple diagrams operating through an entire day with just a five-car set instead of a 2x5.
I have never denied that short-forming was happening - anyone can see that it happens by looking at Journeycheck, but it has never been routine, regular, a matter of course, a deliberate systematic policy, or anything else of the sort.
All I - and others - have tried to do explain some of the things going on that were causing the situation, not least delays to the initial training problem (something that is still causing issues, as noted by Clarence Yard only yesterday) and the delayed delivery of the five-cars 800s.
That is not saying "all is wonderful, nothing to see here" - just an attempt to counter the endless tide of negativity from you and others, whether you like it or not.
As has been noted I don't know how many times now in this thread, HSTs broke down on occasion over many years.
They still do - like yesterday morning on the Cotswold Line.
If the issue was at Paddington, faulty Bristol, South Wales and West Country HSTs got replaced by sets taken off Oxford/Cotswold Line services, with those services then 'short-formed' by a 180 or Turbo stand-in. Nothing new under the sun and all that.
But I don't suppose you were bothering to look out for three coaches instead of eight on an Oxford service or five instead of eight on a Worcester train, were you?
Yes I did.
They are multiple units. They are equipped with underfloor diesel engines. For the vast majority of the route mileage served they are powered by these diesel engines.
Theretofore it seems reasonable to refer to them as DMUs.
Advocates of the new trains dislike the term "DMU" because the average non technical rail passenger tends to associate DMUs with a downgrade to shorter trains and reduced on board facilities.
It was long-standing practice to refer to the Southern Region's units with electrical transmissions as demus, to differentiate them from the designs with mechanical and hydraulic transmissions used elsewhere in the country - referred to as dmus.
On that basis, the 80x trains are demus when operation is in diesel mode.
And as you have indicated, the only reason you refer to them as dmus is because you think it is pejorative and puts the 80xs on a par with something like a 1950s BR dmu. How, er, amusing... just another repetitive element of your repetitive posts here and elsewhere.