If they trained enough Drivers and opened new depots are they still in the wrong or will that just be another excuse to bash GTR ? They could recruit another thousand Drivers and open end to end depots with 50% extra service cover and get 10 extra units 700s and they would still be hung, drawn and quartered.
The reason GTR are getting hung, drawn & quartered is because between May and now they have consistently failed to deliver their published timetable. Given that delivering the published timetable is, kind of, the main raison d'etre for a train company existing, I'd say that's good reason for them to be hung, drawn & quartered.
Perhaps if they'd trained enough drivers and opened new depots *before* the go-live date, not forgetting that the May go-live had already been considerably descoped from what was originally supposed to have been delivered, then they might only be getting hung, drawn & quartered for the inherent Thameslink unreliability, instead of other things on top of that like driver-related cancellations (and, it seems, Undesiro unreliability). Then the finger of the hanging, drawing and quartering might have pointed more towards the DFT.
It's a pretty basic understanding within the industry that when you're delivering a "project", some consideration needs to be given to what resources are going to be needed during the transition period, in order to allow one to continue the "business as usual" activities (i.e. running a train service) alongside the extra requirements associated with the project, i.e. training and cover for movements. Clearly if any planning was done then the wrong conclusions were reached, but one can't help but get the feeling May was planned based on hope rather than on any sound basis. The fact that GTR and Horton were going on record in the day or two before the first Monday morning and predicting "minimal" impact suggests a grossly inept management involved in the delivery of this change project. So if GTR are getting upset at being hung, drawn & quartered over this, they only have themselves to blame.