# Tikz-cd natural transformation diagram [duplicate]

I would like to make the diagram

\documentclass{article}
\usepackage{amsmath,amsfonts}
\usepackage{tikz-cd}
\begin{document}
$\begin{tikzcd} A \arrow[r, bend left=40, "H\circ r", ""{name=U}]\arrow[r, bend right=40, "K", swap, ""{name=D}] &\textbf{Abcd}\arrow[Rightarrow, "\eta", from=U, to=D]. \end{tikzcd}$
\end{document}


perfectly symmetric. I've been trying to change the parameters after the bend left/right option but I don't think this is the right way to proceed. Is there a standard way to act, which is "robust" with respect to the whole diagram?