For a supplement to relativity, I would prefer a book that made explicit connections with relativity.
"How can mathematics be used to model the physics?"
The three books you listed are written by mathematically-oriented relativists
It's difficult to pick one.
I offer my opinions as a physicist interested in geometrical formulations.
If the focus is relativity, I would choose
B. O'Neill: Semi-Riemannian Geometry with Applications to Relativity
or
F. de Felice & C.J.S. Clarke: Relativity on Curved Manifolds
If the focus is relativity and other physical topics, I would choose
T. Frankel: The Geometry of Physics (who also has a small book called Gravitational Curvature )
or
P. Szekeres: A Course in Modern Mathematical Physics: Groups, Hilbert Space and Differential Geometry
B. Schutz: Geometrical Methods of Mathematical Physics
would be good as an overview... but you might find yourself looking elsewhere for more details.
I admit that I'm not so comfortable with Nakahara.You might find these useful:
http://www.math.harvard.edu/~shlomo/docs/semi_riemannian_geometry.pdf
https://projecteuclid.org/euclid.bams/1183539848 (article by Sachs & Wu., who also have an old book "General Relativity for Mathematicians")
http://math.ucr.edu/home/baez/physics/Administrivia/rel_booklist.html