This problem isn't exactly Arabic-specific, it's just super easy to trigger in Arabic. You've got kerning in the Latin script as well, and you could theoretical

This problem isn't exactly Arabic-specific, it's just super easy to trigger in Arabic. You've got kerning in the Latin script as well, and you could theoretically have a font that makes `the` look smaller than `th`. But in Arabic, letters change form based on where they are in the word. All three things with two dots on them are the same letter in تتت, but the middle one is much smaller. I can imagine something like يم being truncated to ي and the end result being longer visually, depending on the font.