I'm trying to work out how I can replace Rails' asset pipeline without getting a headache caused by overwhelming number of node-based tools I'd have to install.

Having one tool + make sounds like something I'd gladly adopt.

https://github.com/williamcotton/makeify

It didn't just eliminate the use of gulp for much things, but also minimized the boilerplate I needed to get this stuff done in gulp.

Everything is just a "loader" away and doesn't need much configuration.

I even got rid of Bower for most libraries.