Zooker, I'm guessing you see this move (LCY to Swanwick) as a precursor for tower controllers simultaneously controlling more than one airfield/runway?
That is a valid concern - and one which would face fierce opposition I'm sure.
But there's no suggestion, certainly from what I've read/seen, that anyone is saying that LCY controllers would have to get dual-valid at a.n.other airfield and provide both services simultaneously.
Probably be better to stick to facts rather than fiction. Should such a hypothetical situation be the case then that's the time to challenge it.
As the case is, it's a question of whether a controller can operate using video rather than seeing out of a set of windows. That point has been proven (albeit at lower intensity airfields).
If it's safe to do it at low intensity airfields what's to prevent it being used at high intensity airfields?
A low intensity airfield might involve 3 aircraft an hour, but they could be concentrated in a 3 minute period - what's to prevent that same 3 minute period being replicated 20 times in an hour?
If it's safe to do it's safe to do.
It's the same job, regardless of the scale. If the equipment is fit for use, and the controllers are suitably trained, then the bigger question is why not, rather than why?