The big council estates in the arc beyond Queens Drive to the M57 -Speke,Halewood ,Netherly,Huyton,Norris Green Fazakerly etc were built to house people from central Liverpool as the old tenement slums were cleared in from the 1930s onwards.
Kirby,Skelmersdale and large areas of Runcorn were developed in the 50s and 60s as new towns again housing people from central Liverpool.
As late as the 1970s you’d hear old people with full wooly Lancashire accents in Huyton village ,Roby and Knotty Ash as a reminder of the pre Livetpool expansion.
Whiston is different and while the Scouse accent has infiltrated in recent years they wouldn’t consider themselves Liverpudlian in the same way .