They’re considerably bigger than even the normal non-Mini iPhone. They’re only just smaller than the iPhone 17 Pro Max: https://phonesized.com/compare/#1863,2767,2760,2738,2736
(I've just noticed you also used wrong models in your original comparison - while both phones are larger than the mini, the difference isn't as large as your link suggests)
* iPhone Mini: 132 x 72 x 8 (https://support.apple.com/en-gb/111877)
These two alternatives are noticeably larger:
* Vivo X300: 151 × 72 × 8 (https://www.vivo.com/in/products/param/x300)
* Oppo X9S: 157 x 74 x 8 (https://www.oppo.com/en/smartphones/series-find-x/find-x9s/s...)
In fact, they're more like the size of the full size iPhone, which, if you're sticking with your iPhone Mini because the iPhone is annoyingly large, means they're too large.
* iPhone 17: 150 x 72 x 8 (https://www.apple.com/uk/iphone-17/specs/)