Ubuntu (or rather Debian) packages of Qt5 are more fine-grained, i.e. mostly by modules not by git repositories. However there are meta-packages corresponding to repos: see e.g. https://packages.debian.org/sid/qtbase5-dev. The bigger packages are easier to maintain, so I'd like to stick with them for now.

If we need to match Ubuntu/Debian one day, we simply make smaller packages and use meta-packages for the current names. The only confusing names are Maemo's qt5-declarative (= quick2 + qml) vs Debian's libqt5declarative (= quick1). But choosing a name that neither matches modules nor repos is even more confusing.

Binary compatible application packages for Ubuntu (touch) and Maemo will IMHO not happen, since each platform needs some minor quirks.