Difference between QConcatenateTablesProxyModel and KConcatenateRowsProxyModel

[Fusion Future]

Recently I notice that since this commit
(https://invent.kde.org/plasma/plasma-workspace/-/commit/25f4cce3bf81ed8412e5053eeddd22d4366fe6ab),
plasmashell will crash at start, and the backtrace indicates that
QConcatenateTablesProxyModel is incompatible with LauncherTasksModel.

The backtrace can be seen from https://bugs.kde.org/show_bug.cgi?id=445479

I would like to know the difference between
QConcatenateTablesProxyModel and KConcatenateRowsProxyModel, because
simply replacing KConcatenateRowsProxyModel with
QConcatenateTablesProxyModel seems problematic.

Thanks in advance.