Why would we sign a soon to be 28 year old who has never registered more than 5 assists?
This is my continual problem with the disconnect between supporters and reality. Dribbly wingers are some of the most "exciting" players in the game because that 1v1 take on is one of the most exciting things in football. But winning it means fuck all if you don't convert it into a goal or assist which is the only thing that actually wins matches.
Mitoma has 0.34 crosses into the penalty area per 90. Johnson has 0.25.
Mitoma has 1.94 shots per 90. Johnson has 2.73.
Mitoma has 0.29 G+A per 90. Johnson has 0.49.
Mitoma has 3.43 progressive passes and 10.8 progressive passes received per 90. Johnson has 3.04 and 9.32.
Mitoma has 5.49 progressive carries per 90. Johnson has 2.86.
Mitoma has 1.03 tackles won per 90. Johnson has 1.24.
Mitoma has 4.86 take ons attempted and 2.11 successful per 90 (43.5%). Johnson has 1.74 attempted and 0.87 successful (50.0%).
So Mitoma runs at players more often, but has a lower success rate. He converts this into roughly the same crosses and significantly fewer shots, ultimately contributing fewer goals and assists. He also has fewer tackles attempted and successful (despite playing for in a team with worse possession statistics).
He's not a bad player. But he's 4 years older than Johnson and not a substantially better player in any way other than he runs at people a lot more often (and, again, does so less successfully). But the inherent bias created in supporters' mind by the dopamine laced excitement of watching a 1v1 take-on fools some into thinking he's a more effective player.
If we don't think Johnson is a great RW, why would we want Mitoma on the LW?