In our strangely over-centralised country, massive changes are under way. The Government has set out a near-comprehensive vision for the sector, alongside both the willingness and the political capital to act upon it.

Which is not to say the process will be easy. Together, reorganisation and devolution will be a recipe for turbulence. The goal? A simpler two-tier system composed of strategic authorities to co-ordinate the big picture and local authorities to do the statutory delivery hard-yards.

Scale is not a side-show, it is the whole rationale for devolution. Many strategic authorities will lack the critical mass to take on major economic or infrastructure responsibilities. Some will govern areas that are simply too small to exert meaningful influence, while others will be trapped in a balancing act between competing local interests.

But there is a risk all this effort will produce a system that is not quite right. The reason may be hard to swallow.

Government wants to fill in the map with real, strategic, regional governance. But the truth is, some of the strategic authorities that are going to emerge from this process simply will not be up to the task. To some extent this can be fixed by going further than the English Devolution White Paper and ensuring these bodies, as they acquire their integrated settlements and take on more powers, are genuinely able to operate in a decisive, flexible and well-resourced way.

But in some places the issue will be – already is – more fundamental. Some strategic authorities will simply be the wrong size. Too large to remain purely local, too small to function as real regional entities, they are unlikely to bear the weight of genuine decentralisation.

Scale is not a side-show, it is the whole rationale for devolution. Many strategic authorities will lack the critical mass to take on major economic or infrastructure responsibilities. Some will govern areas that are simply too small to exert meaningful influence, while others will be trapped in a balancing act between competing local interests.

Whitehall will hesitate to hand over significant powers to what is sure to be an uneven patchwork of varying capabilities and populations.

So, paradoxically, to get a more coherent tier of government, we must recognise different regions will operate differently – with distinct planning, infrastructure and public services needs based on their different geographies, economies and population densities.

As I argue in my recent essay, Rebooting Regionalism, the current model lends itself to a kind of ‘hub-and-spoke' approach, where economic activity is concentrated in a dynamic urban core. In places like Manchester and the West Midlands we should build upon that model with fiscal devolution and other powers, incentivising economic growth that can then be spread to the other parts of the system.

But in other parts of England, the appropriate model is a ‘polycentric' one. Places like East Anglia, Cumbria and the South West are not so easily defined by a single dynamic urban hub. They call for lateral connectivity, specialised and complementary economies in sub-regions.

In such places, you don't need a metro mayor, but you might want a governor to help define and give voice to the common interests of a population spread over a significantly larger geography.

This would be a recipe for regional governance based on finding the model that best fits the regional conditions and ensuring consistently-sized populations.

No more fragmented fiefdoms without the heft or scale for genuinely strategic action, but an array of robust, coherent regions with the muscle to act decisively, and the internal flexibility to allow sub-regional identity and specialisms to flourish.

Devolution should be about building institutions that are strong enough to take on real responsibilities, with the resources to match. We cannot afford for the exhausting processes of reorganisation and devolution to end up with strategic authorities as an end-state. Instead, we must accept that they may be the bridge to a more ambitious model.

Dr Simon Kaye is policy director of independent think-tank Reform