There were plans to replace Queen St and Buchanan St with a new Station called Glasgow North , also replace Central and St Enoch Station with a New Station Glasgow south. Neither were followed through. However imagine that we had these today how many problems would
Have been readily resolved without huge financial costs.
Am I misunderstanding the question?
It is not obvious to me that the two conceptual stations would have resolved
any problems. Surely very few people would have really benefited by being able to interchange between 'Queen Street' services and 'Buchanan Street' services at Glasgow North on 'in-and-out' trips like Cumbernauld to Croy. These were subsequently achieved simply by diverting surviving Buchanan Street services into Queen Street anyway.
Presuming that the new stations were on totally new sites there would have been an inevitable loss of the connectivity between High Level and Low Level services at both Queen Street and Central. So Glasgow would have still had four 'city centre' stations.
I am also unclear how the proposals might have been realised "without huge financial cost".
Both of the mega-stations would presumably have had to be more on the fringes of the city centre (unless most of it was going to be demolished), so general convenience would have been worsened; and for passengers still having to interchange between the two the distance would have been even greater.
It sounds like some fascist architect's dystopian vision.