https://www.football365.com/news/opinion-no-winners-de-gea-henderson-battle-man-unitedI thought this article did a good job analyzing United's current GK plight. For all the talk that De Gea should be moved and has underperformed, Henderson hasn't exactly made the decision a no brainer for United. He wasn't bad by any stretch of the imagination. But he hasn't been spectacular. And his relatively short resume of success is no guarantee of sustained success at United. I understand the notion that United need to look at a 3rd player to take the #1 jersey.
I'd personally give the job to Henderson, try to move De Gea, and try to get a veteran who was OK with being a backup should Henderson succeed but is perhaps intrigued by the possibility Henderson might not. SAF backed De Gea A LOT in his first year or so in spite of a number of high profile gaffes and calls for De Gea to be removed. But he backed him and it worked out pretty well for United. No reason why Henderson shouldn't get that same level of support, IMO. Henderson's errors against Liverpool were nowhere near the level of De Gea's when De Gea was young.