yeah i was at a startup that had SVP of product and SVP of engineering. For the entire year I was there 60% of the time was spent in meetings where they just blamed each other. Engineering would say product didn't tell us what to build so we just built what we thought they wanted and product would say they told engineering what to build but they did it incorrectly.
The company I am at now has a leader who has product and engineering reporting to them for their charter basically following the mini-ceo/cto you described. It has its issues but works much better than the alternative.