The MacBook has more thermal headroom than the iPhone. In theory one should be able to exploit that difference to get better performance in a MacBook form factor.
All of this Geekbench minutiae is missing the point. Apple is rapidly improving the performance of their ARM based CPUs and it won't be long before laptops are at risk - especially with iPad pro and future variants.
A10 is on deck next year and the foundries are iterating on finfets at what seems to be a faster rate than Intel.
Don't forget that Apple has successfully recruited several very seasoned Intel CPU engineers including a "fellow". Intel does not have a monopoly on smart engineers.