I think Tahm will become really good

tahm kench trades well but thats not really his problem, his E makes other laners cry because he can essentially chop damage to him overall in 1/2, however the problem lies in his incapacity to gank well, he has no mobility to catch up to someone who dodged his ult (the enemy warning delay should help though) and the fact that for any smart jungler he's essentially free food, in comparison to shen he lacks the same utility as shen can provide health to an ally (vorpal blades) protect an ally (stand united) has a purely global ult (stand united) ally doesn't lose effectiveness has a shield has a mobility spell and has more easy to land CC in his E, against tahm who; Has a pseudo global in his ult, lacks mobility his way to protect an ally is to stop them from doing anything and he has to walk up to someone to allow him to stun them without the same mobility say an irelia has. Tahm kench has strong damage but low mobility which makes him very gankable in lane so overall he'd be best in mid-lane but even there he lacks any strong utility other mages would have and is still very vulnerable to ganks.

Wits end is great for attack speed on him.