Last month I asked [this](https://tex.stackexchange.com/questions/592718/fixed-indent-for-paragraph-from-left-margin-regardless-of-counters-width) question and I got a response that mostly solved the problems I had, however I noticed that the answer has a small problem (a tiny amount of misalignment), here is my MWE:

```
\documentclass[letter, 12pt]{article}

\usepackage{titlesec}
\newcounter{globalparagraph}
\titleformat{\section}[hang]{\bfseries}{\makebox[0.75in][l]{\thesection}}{0pt}{}
\titleformat{\subsection}[hang]{\itshape}{\makebox[0.75in][l]{\textup{\thesubsection}}}{0pt}{}
  \titleformat{\paragraph}[runin]{\normalfont\normalsize}{%
  \refstepcounter{globalparagraph}%
  \sbox0{[0]}\makebox[\dimexpr0.75in-\wd0][l]{\theparagraph}}{0pt}{}
\setcounter{secnumdepth}{4}
\renewcommand{\thesection}{\Roman{section}.}
\renewcommand{\thesubsection}{\Alph{subsection}.}
\renewcommand{\theparagraph}{[\arabic{globalparagraph}]}

\begin{document}
\section{ONE}
\subsection{SubSection}
\paragraph{} \textit{Subsection}
\end{document}

```

Which outputs:

[![Output](https://i.stack.imgur.com/l8ZcD.png)](https://i.stack.imgur.com/l8ZcD.png)

As you can see the start of the paragraph is not fully aligned with the section and subsection titles. I think the dimension of the box needs another tweak but I don't know what that tweak is.