The apps are already individual things that don't depend on each other, except in some cases where KParts are used. A KPart is kind of like an application turned into a library. Usually, this is not something users need to be concerned about. The integrated terminal in the Dolphin file manager is a Konsole KPart. openSUSE (and probably others like Fedora and Ubuntu) actually split Konsole into `konsole` and `konsole-part`, so it's not a problem.

That sounds like an Arch packaging issue, a misunderstanding of what the packages actually do or you're installing a metapackage and not realizing it.