sorry chap but... https://en.wikipedia.org/wiki/Regions_of_England they're official regions.
Although the regions of England are official, they are a bit redundant. They were created for an attempt at reforming local government that never happened and they hold no historical significance either. They're only used for government statistics and elections for the EU parliament.
But, if you're going by regions, then you should call "South East England" "Mainland South East" and call "South West England" "Mainland South West England" because you've included the Isle of Wight and Isles of Scilly as separate territories despite the Isles of Scilly being part of South West England and the Isle of Wight being part of South East England.