Why isn't Toadette / Baby Blooper #1?
This calculator can only see the raw stats provided. It lacks access to crucial "hidden" statistics like hitboxes. For example, while the Toadette / Baby Blooper combo has identical stats to combos like Peach / Mach Rocket, many prefer it because of its wider hitbox that makes latching onto rails easier and that it won't be knocked over. These are real performance factors the calculator cannot account for.
Linearity Assumption
You will also notice that Toadette / Baby Blooper has an identical score to many other Baby Blooper combos. This exposes another flaw of this calculator as for simplicity and ease of use, this tool assumes all stat points are equal (i.e., the gain from 1 to 2 speed is the same as from 8 to 9). In the game's actual code, stats may have diminishing returns, making our linear model an approximation. Additonally, stats like handling naturally have nonlinear value. This is why combos that are known to perform worse than others in practice can get the same score on this calculator.
If I can get feedback from experienced players about default weights and non-linear values, I hope to add them in a future update!