I'm going to say that Mr Mime definitely needs to move down. Even with the ability to learn Thunderbolt, hardly anyone is going to get the TBolt TM at that time(since it's one of the Game Corner TMs), and Mr Mime isn't that easy to find either. He's at most equal to Natu.
Stantler's main attraction is that he has fully evolved stats at the time, but his main problem is that he is weak to the Fighting Gym, can't hurt the Steel Gym, has no super effective STAB, and in fact will be running Stomp/Confuse Ray until level 38 when it gets Zen Headbutt.
You could teach him Shadow Ball, but that also has little SE coverage, and you'll have trouble with fighters.
Stantler has Intimidate and Hypnosis, true, but he will have a hard time killing things unless you level him up a bit.
Stantler's main attraction is that he has fully evolved stats at the time, but his main problem is that he is weak to the Fighting Gym, can't hurt the Steel Gym, has no super effective STAB, and in fact will be running Stomp/Confuse Ray until level 38 when it gets Zen Headbutt.
You could teach him Shadow Ball, but that also has little SE coverage, and you'll have trouble with fighters.
Stantler has Intimidate and Hypnosis, true, but he will have a hard time killing things unless you level him up a bit.