Mastiffs are good dogs... I've had several breeds based on them ( bulldog and boxers ) and they make fine companions.
Number 2 is a 2-1/2 year old Pug. He's pretty much in charge except when the cat is.
Then there is our small EBUD (Emergency Back-Up Dog) in case either of the Primary Dogs go into Failure mode. He's a one year old Papillon.
He's got two speeds. Sound asleep and Bouncing Off The Walls.
BTW, you don't know if Candied Cashews and Gummi Bears are toxic to dogs do you? No reason for asking really. I just want to have that little bit of info handy, just in case.
Sorry about the loss of your friend and best of luck with the new one.
L