In response to this statement.

When the first Polish Hussars were "created" They had no armor. And only had a lance, saber and a shield. The original purpose of having little equipment was to rely on Speed and maneuverability during battle.

During the 16th century, the Polish King reformed the Hussars, to now have armor, but to still be able to move very quickly during battle. This was when the Hussars were made the standard of the Polish Army. They were very, well-trained and well-equipped.

An example of this was 18 months after the reform, 1400 winged hussars faced a rebelling force of 12,000 soldiers. The Polish Hussars charged the flank of the rebel forces and crushed them. It was seen as an outstanding victory. Seeing, around 4400 dead and a further 5000 taken prisoner. Whereas the Polish Hussars only lost 88 men.

During a cavalry charge, the hussars followed an advance order. The first order was. for the first 75 meters, the rider and the horse would walk at a steady rate. The next 150 Meters would be a trot. Which would then form from a trot to a canter, then finally becoming a gallop. The final charge which would be 30 meters was done at a canter.

This method was used to preserve the horse's energy during the charge. Especially in the case if the Hussars would have to charge multiple times or a final pursuit of the enemy.

So from this, we can see that the Polish Hussars would rely on two major factors in battle. Equipment and energy. This is what made them very effective.

The wings on riders back are believed to of been used to intimidate the opposing foe. Due to how strong and fierce the rider would look.

And finally, the Lancer. The lancer ranged from 4.5 to 6.2 Meters. Due to its length, the lancer had to be considered light and easy to maneuver. The point of the lancer was made of steel reinforced with additional metal straps, to prevent the wood from any saber cuts.

So Overall The three concluding factors are, speed, The weapon, and energy. Plus tactics on the sidenote.

sources http://museum-of-artifacts.blogspot.co.uk/2015/11/polish-winged-hussars-best-cavalry-in.html https://www.mhistory.net/polish-winged-hussars-the-most-effective-and-beautiful-cavalry-in-the-world/

Hope I managed to answer your question in a simplified version! :)

I, by far, am not an expert on history, or this topic in particular, but in regards of:

such as Vienna where they beat 100,000 Ottomans with 27,000 hussars

You mean, including the imperial and polish Infantery, imperial cavalry (which also took part in the cavalry charge) and the defenders...

You're making it sound as if the Polish Cavalry did the whole job. Afaik the Ottoman army got battered by the infantery of the League and the cavalry charge basically sealed the deal.

From what I've read, the Holy League could field between nearly 80,000 and 90,000 troops VS up to 140,000 Ottomans.