@wolftune My understanding, correct me if I'm misremembering, is that a quota rule for cardinal methods like this is ensured if voters bullet vote, Party List style, but not necessarily if they don't. This seems like an edge case example of that, and it does seem like an edge case, but it raises good questions. (That I'm planning to post in a dedicated thread soon, when I have time to engage with the replies.) Namely, the definition of proportionality used for ordinal methods is pretty crude for describing Cardinal or Condorcet PR.
Cardinal PR (unlike Ordinal) can allow voters and factions to coalition naturally (even if the candidates or parties don't) by addressing vote-splitting, and they also combat the notorious PR polarization stagnation that academics warn about, but they can't also always fend off against the mythical homogenized centrist who everyone agrees is meh.
This is an example of why I like STAR more than Score, and we haven't fully applied those principles to PR.. yet. I still think a hybrid approach is the key to unlocking that next level.
Our STAR-PR committee looked at a few options for selection, including highest score (simplest) and Monroe (which I think would address this.) Highest score won out, but realistically the two were pretty well dead tied.
In any case, I think that Clones are a much bigger problem in hypothetical math scenarios than they ever will be in real life campaigns, and if a faction can really pull off running 2 or 3 clones that all break through and win over voters then that's frankly impressive. The reality is that if voter behavior doesn't do them in, limitations in campaign funding and volunteer power likely will.
I'd still take STAR-PR edge cases over STV edge cases, but I won't claim it's perfect and that nobody will ever come up with something even better. This is still the cutting edge of voting theory.