Same as Barb, I use a slicker on the cats. The slicker and the rake and a zoom groom on the dog. The frurminator can remove undercoat if used too much or improperly so it scares me, I'd be sure to use it wrongly. I don't actually have a zoom groom, instead I bought a rubber curry comb at horse tack shop for way, way less.
Sure, go ahead, try a brush attachment on the vacuum on the cat. Tell us how that works out. LOL, kidding.
I think you meant on the dog. Honestly, I have dogs who don't mind the vacuum but I don't think it would solve your problem. The brush does all the work. All the vacuum will do is catch the hair once it's out.