Careful consideration shows you are quite correct. Who can forget the Falling Machine, after all? Gil seems to be a well rounded Spark. And yet, he built Zoing when he was 8. He put Punch and Judy back together; and apparently improved them in the process. And he was the one who knew how to set up the Si Vales Valeo Rolling Resurrection Chain, AND about the secondary process. He's VERY good at biology.
Which is good because Agatha admits she sucks at it.
Tweedle's apparently got superhuman strength all the time, though.
Tarvek was able to beat Zola, who took the worst Higgs could dish out, to a pulp and was throttling her when Gil interrupted. But I'm not sure that was the madness place so much as unholy rage at her injuring and trying to kill Agatha. In fact I'd note BOTH Gil and Tarvek seem to reach otherwise unattainable levels of physical power when Agatha's threatened.
Also, Gil's cheating. He took a point blank shot to the chest from Dr. Merlot and was only bruised. Klaus obviously enhanced him just as the Mongfishes enhanced Tarvek.