You have your hands full with these two! they are so much like children. I would leave Howie in your bedroom where he feels most comfortable. Your new puppy can be in his crate while you guys are gone.
I don't have experience with this, and Howie has been your number 1 for so long. or course he is going to be angry at this "intruder." It takes patience and consistency. Yoyr Howie will come around eventually. He will be chalenging for a while though, and have a big attitude.
