And you seem to be looking at it like a microcontroller, but I think it's meant as a general purpose application processor. Like, you could watch a youtube video without ever waking the compute tile. But that means it has to be software compatible with the other cores. Might be a real pain for Arrow Lake in particular.
That almost sounds like a 3rd hybrid cluster for light application duties. Sounds like a minefield to me. The reason I thought a simpler CPU would work is because on a typical system you aren't just running a browser with a video. It also isn't because you have too many tabs open. It's that there's a rogue thread or driver that refuses to cooperate.
And it's so common because that's how complex the Windows ecosystem is.
-Obscure Chinese SSD vs a well known SSD from a good manufacturer
-Needing a driver version that's not available on the manufacturer support site but may be available using driver retrieval software(which often is shady).
-The driver/firmware of the hardware is simply buggy. And since it's something like a webcam or a fingerprint device, you can't do anything about it.
So ideally if a dedicated core can do all that without needing a special driver then you can keep the main core in the lowest C state when necessary. And you don't need it powerful enough to run even a browser.
Also specifically regarding Intel I believe their off-die PCH is hampering them. As an IDM they are also concerned with maximizing their fabs so moving the main chips to a full SoC would mean loss of utilization. In their eyes they needed EMIB/Foveros before dealing with this despite them likely realizing they need a form of on-die chipset.