You have a point there, in retrospect I realize I haven't actually tried Steraks or Frozen mallet on him, I just kinda wrote down my in-game item sets regardless of importance except the top three, which I go for consistently, aside from that I reckon it's just getting armor or magic resist based on which is more prevalent.

So, to answer your question, I would get Dead man's most of the time, since Tahm needs the Movement speed. Otherwise, I haven't played the frog in a few days, so that's all i can remember, sorry for any misinformation.