You're right that there are two different parts to a these, but I think they both benefit from graphical tools.
I'm talking about a VCS tool telling me that the rebase had got to commit n of m and a conflict has been encountered, and which files have conflicts resolved (either automatically or I've manually resolved then so far in this tool), and which other files have conflicts outstanding. Then I can invoke the three way merge tool from there (which is indeed hugely better than a command line tool). Something like this (except this is for Hg):
I'm talking about a VCS tool telling me that the rebase had got to commit n of m and a conflict has been encountered, and which files have conflicts resolved (either automatically or I've manually resolved then so far in this tool), and which other files have conflicts outstanding. Then I can invoke the three way merge tool from there (which is indeed hugely better than a command line tool). Something like this (except this is for Hg):
https://i.stack.imgur.com/kaFNz.png