Heroes 5.5 WarGame Edition - Tactical Edition.

At least, I haven't found any historical evidence to support the idea that cavalry would routinely defeat second-rate infantry in large numbers (i.e., with ratios close to 1:10).

I haven't found anything like that either. The only thing you could argue is desertion by frightened soldiers, but that wouldn't work against pikemen or heavily armored infantry (heavily armored infantry is ridiculous - a two-handed sword + a huge shield). Overall, cavalry seems weak - a spear is practically impossible to use effectively without a charge, and a sword on the belt looks ridiculous compared to the "club" of the heavily armored infantry. However, griffins look scarier than knights - if you imagine their attack on the enemy, no defensive ditches will save them. A griffin will attack from above and scatter everyone, and the rest will run away or grab whatever weapon they can find.
A griffin should be stronger than a knight.