How to vertically align overset (and underset) and overbrace (and underbrace) consistently across items?

Question

How can I get the items within overbrace and overset to be vertically aligned with one another? This would mean that, in the example below, the numbers 1-8 would be in the same row, and not vertically staggered.

Thank you.

${\overbrace{
    \overset{\text{।}}{\text{स}}
    \overset{\text{।}}{\text{मु}}
    \overset{\text{ऽ}}{\text{हा}}}^{1}}
{\overbrace{
    \overset{\text{ऽ}}{\text{लो}}
    \overset{\text{।}}{\text{अ}}
    \overset{\text{।}}{\text{ण}}}^{2}}
{\overbrace{
    \overset{\text{।}}{\text{वि}}
    \overset{\text{।}}{\text{डि}}
    \overset{\text{ऽ}}{\text{अं}}}^{3}}
{\overbrace{
    \overset{\text{।}}{\text{वि}}
    \overset{\text{।}}{\text{डि}}
    \overset{\text{।}}{\text{अ}}
    \overset{\text{।}}{\text{णि}}}^{4}}
{\overbrace{
    \overset{\text{ऽ}}{\text{मिल्}}
    \overset{\text{।}}{\text{ल}}
    \overset{\text{।}}{\text{पि}}}^{5}}
{\overbrace{
    \overset{\text{।}}{\text{अ}}
    \overset{\text{ऽ}}{\text{दं}}
    \overset{\text{।}}{\text{स}}}^{6}}
{\overbrace{
    \overset{\text{।}}{\text{णु}}
    \overset{\text{।}}{\text{सु}}
    \overset{\text{।}}{\text{अ}}
    \overset{\text{।}}{\text{हि}}}^{7}}
{\overbrace{
    \overset{\text{।}}{\text{अ}}
    \overset{\text{ऽ}}{\text{अम्}}}^{8}}\text{।}\\
{\underbrace{
    \underset{\text{ऽ}}{\text{ऊ}}
    \underset{\text{।}}{\text{सु}}
    \underset{\text{।}}{\text{अ}}}_{9}}
{\underbrace{
    \underset{\text{।}}{\text{हि}}
    \underset{\text{।}}{\text{अ}}
    \underset{\text{ऽ}}{\text{उम्}}}_{10}}
{\underbrace{
    \underset{\text{ऽ}}{\text{मिल्}}
    \underset{\text{ऽ}}{\text{लं}}}_{11}\text{ }}
{\underbrace{
    \underset{\text{ऽ}}{\text{उम्}}
    \underset{\text{ऽ}}{\text{मिल्}}}_{12}}
{\underbrace{
    \underset{\text{ऽ}}{\text{लो}}
    \underset{\text{।}}{\text{स}}
    \underset{\text{।}}{\text{रि}}}_{13}}
{\underbrace{
    \underset{\text{।}}{\text{अ}}
    \underset{\text{।}}{\text{प}}
    \underset{\text{।}}{\text{इ}}
    \underset{\text{।}}{\text{मु}}}_{14}}
{\underbrace{
    \underset{\text{।}}{\text{ह}}
    \underset{\text{।}}{\text{कि}}
    \underset{\text{ऽ}}{\text{लिम्}}}_{15}}
{\underbrace{
    \underset{\text{ऽ}}{\text{मन्}}
    \underset{\text{ऽ}}{\text{तिम्}}}_{16}} \text{॥}$

Answer 1

I cannot use your fonts but you can use \vphantoms, I think.

\documentclass{article}
\usepackage{amsmath}
\begin{document}

$\overbrace{\overset{a}{a}\overset{a}{a}\overset{a}{a}}^1
\overbrace{\overset{b}{b}\overset{b}{b}\overset{b}{b}}^2$

$\overbrace{\vphantom{\overset{b}{b}}\overset{a}{a}\overset{a}{a}\overset{a}{a}}^1
\overbrace{\overset{b}{b}\overset{b}{b}\overset{b}{b}}^2$
\end{document}

Answer 2

With longstacks, the baselineskip is fixed, which I think you want to align all baselines. Also, the underletters are set in text rather than math, which I think you also want.

\documentclass{article}
\usepackage{amsmath,stackengine}
\newcommand\notate[2]{\stackon{#1}{\scriptsize #2\strut}}
\begin{document}
\def\stacktype{L}
\setstackgap{L}{8pt}
${\overbrace{
    \notate{a}{I}
    \notate{b}{I}
    \notate{c}{S}}^{1}}
{\overbrace{
    \notate{e}{s}
    \notate{e}{i}
    \notate{e}{i}}^{2}}
$
\end{document}