Presumably the PoCo will examine the plans and refuse to connect if they consider the circuit arrangements unsuitable.
That would certainly ensure that the installation is likely to be able to supply the expected load without nuisance tripping and so on, so from that angle it is a good thing. That said, however, problems such as this that I see in England are most commonly caused not by the original circuit design but by indiscriminate extensions and extra heavy loads that have been added over the years by various home-owners.
