The main problem for the Wizards the last few years have been droughts, droughts, droughts.
They always have a few stretches (usually in the 3rd quarter) where other teams go on an 8-0 or 10-2 run.
This means they need someone to stop the bleeding. The only players who can create their own shot is Wall and Beal (when motivated). That's it.
They really need a post scorer. This does not mean a low-post scorer. Look at how David Lee scored against the Wizards PFs with crafty moves. They need someone like that. There was some talk last year about possibility getting DeMarcus Cousins. I don't like his attitude but love his game.
They need someone to stop the droughts especially against good teams.