Madness was a one hit wonder here in the US with Our House. Plenty of hits in UK.Speaking of one hit wonders. It depends on the country. I saw one of those reaction videos on you tube. Reacting to Simply Minds as a one hit wonder band. Band has had so many hits. Only not in the US. Same with Sinead O Connor. Claiming she was a one hit wonder. In the US both had only one hit. Ireland and the UK they had many hits. Thin Lizzy were also a one hit wonder in the US. Many big hits over here.
Marshall Hain did have two more albums in the 80's. Then the lead singer moved to the US and wrote songs for other people. Music changes. If you can't change with it, you might as well give it up.
Outside the US. To us here they're a one hit wonder. Wiki : They had nine charting singles in the UK, including two number ones, and five top 20 hits in South Africa.Again, many of the groups you brought up mate, are not one-hit wonders. They achieved multiple hit singles in the top ten. Munjo Jerry have actually had two number ones during their career.