When I started my watch collection hobby back in 2010, I noticed that my Tissot watch which uses Roman numerals has “IIII” instead of “IV” for the 4 o’clock position. Originally I though it was a mistake.
However, this is not a mistake. “IIII” has been used instead of “IV” on dials for several hundred years actually. It is really a matter of aesthetics and visual symmetrical balance. Someone a long time ago, noticed that using that for 4 o’clock not only made a dial look visually better, but helped legibility when looking at the dial from different angles. It is called a “watchmaker’s four,” and it’s used for those reasons (definition from ABlogToWatch).