I watch both them a lot. Very similar caliber of players and anyone who picks either and says "easily" or "ainec" is wrong.
They are both play drivers but in different ways.
Mackinnon will hustle his entire line into the offensive zone and immediately snaps a shot or centering pass to create a scoring chance.
Draisaitl is deceivingly fast, but his strength is more East-West play. His stickhandling through multiple defenders and backcheckers is amazing and his play along the boards is the best in the league (imo). He holds on the puck much longer and will stave off defenders to wait out a scoring chance.
Neither is that good defensively. Not as bad as some of here will say, but Mackinnon can get caught trying to do too much, and Draisaitl will make the occasional erratic pass that leads to a turn over. But either way they both mathup against other teams top players and pass the eye test in the defensive zone (imo)- good positioning, big bodies in the way, active sticks.
I'd build around Draisaitl if your team met the following criteria:
You have a goalscoring winger- Draisaitl is the better passer, he'd make more use of a Laine/Ovi
You have a high-end playmaking winger- Draisaitl is the better goalscorer (not by much tho), really nice 1-timer
You have smaller skilled wingers- Draisaitl really uses his body down low and can get physical to cover for a skill guy
Your team has a bad PP- Draisaitl imo controls the ice on the Oilers PP, which is surprising considering they have McDavid
I'd build around Mackinnon if your team met the following criteria:
You have a fast winger- Mackinnon is much better on the rush, driving North/South play
You need a 1 man line- I think Mackinnon could play with less talent better than Draisaitl could, does singlehanded plays more often
You have 2-way wingers- can sometimes cover defensively to allow Mackinnon to play that "thinking breakaway" style that he loves and excels at
While both are elite at essentially all aspects of the game, its obvious by watching playstyle that Mackinnon's number 1 strength is his physical tools where as for Draisaitl it's his hockey IQ.
Interesting enough I think if you put Mackinnon on Detroit, he'd still be a 90+ point player, where as Draisaitl I think would have to work to be PPG. Mackinnon does more with less.
But on the flip side, if you put Mackinnon on Tampa, I don't think he'd improve a ton and would be about a 110-115 point player. However, I think Draisaitl would be looking at 130+ points. Draisaitl utilizes the talent around him better, he will thread a pass only another elite player would think to connect on, or will predict his elite linemates' thinking and find the soft spot in the offensive zone to bury the goal himself.
Gun to my head I would take Colorado's #29. I think Mack is the recipe for consistency and could step onto any team be one of the league's premier players. For some teams (less than 10ish, including Edmonton) I think Draisaitl would be the more effective choice. Neither team would trade their guy for the other and in this instance both teams would be right.
This is as objective of a comparison as I can make.
This choice is by the thinnest of margins, they are close enough that I think the choice between them would be decided by outside factors.