I have found that site to be a bit of a mix of accurate and inaccurate information. Feels like it's compiled by AI.
Interestingly, I distinctly remember researching something on there which was inaccurate for Thunderbird but accurate for Cougar. It may even have been transmission related.
MN12 never had a 5-speed automatic. Lincoln LS, Retrobird, and Jaguar X-Type were the first Ford cars with that transmission, along with Aviator, Explorer, and retro Mustang before 2011.
And I would have to research the actual gearing. But my guess is that that 5-speed actually doesn't differ much in terms of 1st gear and top gear gearing, but rather adds one additional ratio in-between. Which is great of course for outright acceleration; but for me personally, I would prefer a greater ratio spread for more efficient high-speed cruising.