I can take Saga in Milwaukee as an example.

iHeart has the original Oldies station. WRIT. It's 70s-90s hits now, but some people still listen by default. Their closest competition is Saga's WKLH.

How can they chip some of WRIT's audience away to make WKLH seem higher in the overall ratings? Traditional Oldies on a low power signal that does not cover the entire market, 106.9. It does quite well in the 6+ given it's signal. Chips off some of WRIT's older demo and props up WKLH as a result. They can also add that in as a package deal with the other stations from a sales point and they do. Lot of local advertisers run spots on there. National ones, not as much. Little extra money. Keeps the older demo away from the competition.

WSHE is likely used to keep other stations from beating or getting to close to WTMX in the overall ratings. They can also package sell it.

I don't know what iHeart would package sell WCHI with. I would assume WKSC. They seemingly saw a format hole and filled it. Took about a share away from WKQX which averaged around a 3.0 before. Likely that station's upper demo. Lot of the same music. People frequently post videos of themselves listening to WKQX on social media, and 95.5 is almost always a preset next to it.