Horse Stance training

Stance training is a good supplement to training just like yoga would be. I think isometric holds for either the upper or lower body are good for the joints and teaching the body to be efficient. Out of different routines I got the most out holding "Wu chi" for 10-20 minutes with deep breathing and relaxation. If you want more power then do heavy deadlifts and squats. A 100 day kneeling stance routine gave me the ability to effortlessly change levels, and a 100 day horse stance on toes routine put a lot of spring in my footwork. Take any movement and break it down to a posture and you'll physically master it.

Practice pivoting like a door so that you get use to setting up throws and moving out of the way while maintaining structure.

Make sure you are working on your ability to change the levels of your horse stance because judo is more fluid than kung fu when it comes to throws and keeping your hips back is what is keeping you from getting thrown.
I saw in another post you said that you were having trouble throwing bigger guys.

Well first how are they bigger i.e. tall,fat because you maybe trying a throw or takedown on the wrong body type if your hips are lower than work on your ippon seoi nage and remember the key to it is to pull the opponent far enough forward to make him fully offbalance or make him reach out and come to you . Alot of times when your the smaller person you attack more than you should. At home try working on having some one reach out to grab your gi and then you move back just enough to make them rock forward from over extending their weight.Then work on the pivot of your feet so that when you add the two they are loaded on your hips and ready to be thrown. I was a small guy when i trained in jj so trust me work this throw for the taller guys.

Now the fat short guys work your Tomoe Nage and trust it will work and use when your begin rushed back and work UKIWAZA stick to getting good at those and get back to me in 1 or 2 months and you will be amazed.

Horse Stance is great for a lot of things, especially when combined with different exercises, for example:

Alternating front kicks - besides working the kick, it will improve balance
Calf Raises - Calves + balance

Those are just a couple of examples, but as you can see, there are many possibilities besides the obvious of just strengthening of the upper legs...