If you can’t explain their side well enough that they’d nod along, you’re not ready to argue against it.

Arguing against a position you cannot state fairly means arguing against something you invented. Most disagreements run on caricatures, because caricatures are easy to defeat and defeating them feels like progress, while the real position sits untouched. If your version of their view sounds ridiculous, you have not found their view. You have found the version that is convenient for you.

Try writing their case until they would nod at it. Then notice which part is genuinely hard to answer, because that is the argument. Everything else you were planning to say was aimed at nobody.