For context (I didn't realise a new thread had been created), there are some issues with the 701s at the moment (particularly regarding the state of the drivers cabs) and there is a possibility that it will be quite some time before the issues are resolved and SWR actually accepts members of the fleet for service. People pointed out that as he 458s and 707s both have other jobs waiting for them, there could be a unit shortage.
The reduced timetable at the moment will certainly help things. However I am not sure if service levels are reduced enough to be able to release the 707s to go to Southeastern, or the 458s to be refurbished, and certainly not for both.
As far as I am aware they didn't *need* the 442s to operate the full timetable minus the extra Portsmouth services and peak extras in general, but I could be wrong on that. So there's no pressing need for 442 replacements. That being said, they may want to send the 458s to be refurbished sooner rather than later, and it could be possible for some more 450s to go over to the Reading line to cover for them. Once the 458s are done, you'll have even more 450s that can be sent to suburbia to maybe displace the 707s. Again, with the current timetable, there isn't technically a burning need for 707s in southeastern land however I think they are quite keen to have them still to be able to move around/replace some units.
So the main questions are:
Is it likely the 458s and/or 707s will leave their current duties *before* the 701s are introduced (which may be quite a way off yet)?
Is there enough other stock lying around to facilitate this?
And if not, that's when my question of 'could they take something else in for a while' kicks in.