Natürlich geht das. Man kann beliebig viele Optionen durch Komma getrennt angeben. In der pdfpages-Anleitung gibt es dazu auch Beispiele.
Übrigens beherrscht auch \includegraphics die Möglichkeit, die Ausgabe zu verkleinern, beispielsweise:
\documentclass[a4paper]{article}
\usepackage{mwe}
\begin{document}
\centering
\includegraphics[page=1,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=2,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=3,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=4,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=5,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=6,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=7,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=8,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=9,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=10,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=11,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\includegraphics[page=12,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\end{document}
statt:
\documentclass[a4paper]{article}
\usepackage{mwe}
\usepackage{pdfpages}
\begin{document}
\includepdf[pages=-,height=\textheight,width=\textwidth,keepaspectratio]{example-image-a4-numbered}
\end{document}