V/S
Let's see......
Alakazam
Stats
HP - 55
Attack - 50
Defense - 45
S. Attack - 135
S. Defense - 85
Speed - 120
Role : Special Sweeper
Disadvantages : Low HP, Attack, and Defense
Advantage : Awesome S. Attack, okay S. Defense and cool Speed
Moves : Psychic, Recover, Shadow Ball, Energy Ball, Dream Eater, Calm Mind, Future Sight, Signal Beam, Focus Blast, and Psyshock
Good movesets
Mr. Mime
Stats
HP - 40
Attack - 45
Defense - 65
S. Attack - 120
S. Defense -100
Speed - 90
Disadvantages : Low HP, Attack, and Defense
Advantages : Okay S. Attack, S. Defense and average speed.
Moves : Focus Blast, Thunderbolt, Psychic , Shadow Ball, Energy Ball, and Dream Eater.
Mr. Mime is more versatile with moves, and has good S Attack, S Defense and Speed spread.
Good Movesets
Stat wise, Alakazam wins; However, if you tell me which role they would have been, I can tell you their move (dis)advantages to your team.
Hope This Helps :)