If they put the Mustang badge on it, then a V8 option should at least have strong consideration as it's certainly part of the Mustang heritage.
If they want to separate it from the 3.0 Ecoboost, use the Dark Hose variant, and/or give it some more R&D to squeeze out more performance. This would be a performance vehicle, the numbers aren't just for numbers' sake. If the CEO wants Ford to be the "Porsche of off road", that requires the hardware to back the claim.