Looking at the balance by "long range" vs "close range" is not the best way of looking at it due to games being way more impactful close range.
But I will say, MnK players can keep up but you have to put in twice the work and understand that the biggest pro with playing MnK is flexability and survivability.
Other than that, best thing is swapping over.
Apex Legends Devs on Aim-Assist Issue
• Current aim-assist is fair for competitive play
• M&K is better for long-range, and controllers are stronger in close combat
• No single adjustment will fix everything.