I'm a BJJ blue belt that has reason started training Judo. 90% of the time when my black belt sensai is in my guard, he attacks submissions instead of passing. He applies americanas, kimuras, and collar chokes all while stacking and smothering my hips to stop arm bars and back takes. He applies an enormous amount of pressure, making it very difficult to counter attack. Is this a common Judo strategy? And is this a legit strategy? Or is it that I should just drill counter his attacks with armbars and back takes more?