So I finally got a Cali Guy Blaine (coconut scented!) and can finally confirm for myself exactly what the difference is between this and the Tango sculpt. I don’t have my original Generation Girl Blaine at hand, so I’m not sure how big the difference is there, but I have a feeling he’s a bit more angular. The Tango sculpt definitely has less definition, and the best place to spot it is actually the nostrils.
ETA: as has been pointed out, the version Cheerleader Ken has is called the New Tango or Basics Ken, and is a modified version of the original Tango sculpt. Apart from a new neck type, it has slightly flattened, blurry features compared to the Cali Guy Blaine version. So definitely not identical. Also: Tango Ken came out first, and apparently Cali Guy is a slightly inflated version of that sculpt. How they managed to keep his features sharp and detailed I don’t know.
I was vaguely considering modding Cali Guy to fit the Cheerleader Ken body, but mr Cali is more tan and possibly a bit yellowed, so it wouldn’t look good even if I managed to not mess up the neck mod. I guess the search for a decent articulated male body with a perfectly matched skintone is on again.