"Two heads are better than one" and "Too many cooks in the kitchen ruin the broth" also aren't necessarily opposite. It reminds me of the phrase "two's company, three's a crowd". It's possible for two to be better than one while three (or an even larger number) is too many. Another fun saying along these lines is "A man with a watch knows what time it is. A man with two watches is never sure." which seems to usually be used to mean that if you have only one source of information you can become overconfident, whereas if you have two then you won't know which is correct if they contradict, and even if they don't contradict you are more likely to be aware of the fact that they could be wrong. Another one is "a camel is a horse designed by committee"
Would you mind giving the reasons you think it would still be bad if the debt was actually canceled rather than just paid by the government?
I think implementing this policy would require frequent publicization of what issues are on the current list and frequent debates and votes on whether to replace one topic on the list with another topic not yet on the list and would therefore have the opposite of the intended effect. Maybe there's a clever way to get around those issues, but I doubt it.