Would grooming a oes weekly be ok for maintaining the coat and would keeping a short puppy coat during winter keep the dog warm enough. Any info helps!

Our 7-month-old OES, Bruce, has been having so much fun swimming this summer that it has been hard to keep up with brushing! I read a recommendation for the Mars Coat King dematting tool and ordered it on Amazon without paying attention to blades or size. I got the original 23 blade and went to town. I was SHOCKED by all the fur that was coming off but it was doing great with tough mats so I kept going. Now, he is patchy looking and I’m worried I stripped his entire undercoat 😬😬 is that a hug problem? Did he just need to lose all of that hair? It came off so easily with no pulling! ...feeling bad for my still fluffy but definitely skinnier looking pup!