I used to think that Johnson picks Ward apart easily (mainly due to my bias towards Johnson) but looking at it now with a fair mindset I honestly think Ward’s style can disrupt Johnson’s rhythm. Ward was very good at changing distance, frustrating opponents and taking away the opponents best weapons, including the jab. Johnson’s main weakness was his tendency to not switch gears when needed to. As great as he was as a boxer and counterpuncher he overly relies on that approach and I don’t think that’s enough to convincingly beat a clever fighter like Ward, and I say that begrudgingly. Johnson would have to fight a totally perfect fight against Ward. It’s a SD type fight for either fighters for me.
If we're using the (slightly past prime) version of Ward that actually competed at LHW toward the end of his career, I'd say Johnson does pretty much everything better than him and probably wins a convincing decision.