Why couldn't Steve Holland have done the assistant role at both Chelsea and England long term?

[Dancfc]

I read an article earlier about how Craig Shakespeare was Big Sam's assistant at the same time he was also part of the Leicester City coaching staff which also reminded me McLaren combined his managers role at Boro with assisting Sven in the national set up, likewise Keane assisting with both Villa and ROI.

So why bearing that in mind were the rules different with Holland? Soon as he was announced as Southgate's assistant there was a massive media outrage it made his long term prospects combining both roles pretty much untenable. But why wasn't he permitted to do what many before him did?

 

[Samid]

Conflict of interest.

 

[Snow]

I think you'd want your assistant NT manager be working there full time. Why pay someone a full time gig who's not able to perform full time?