reason behind using qpt_plot_combined()

[TejasAvinashShetty]

What is the reason behind using qpt_plot_combined() instead of matrix_histogram_complex()
in the following cnot, toffoli, iswap, rotation ?
Isn't matrix_histogram_complex() up for the task too?
Pardon me for my silly question. But I could not help if the choice was taken to improve the clarity of visualizing the elements of the matrix (So that the matrix elements are far apart.) .
Or is there a deeper reason?
Maybe @jrjohansson or @nonhermitian could shed some light?