Content type with alias 'XXX' has an invalid composition. Property groups with the same alias must also have the same type across all compositions

[ProNotion]

If my understanding of this is correct it is caused by the fact that we have multiple document-type compositions on a doctype that have tabs with the same name?

How is this best rectified during the migration? In the v7 site we are migrating away from, the properties were simply merged onto the same tab.