Re: 1st image of David Bradley as William Hartnell
If anything, the casting works better dramatically if there's a noticeable difference between 'William Hartnell' and 'William Hartnell in wig and costume as the Doctor'.
"Some days are better than others. They say that where I come from."
"Loudly, I imagine, on the day you left."
(Blake's 7 - Rumours of Death)