Iv never had more than 1 bully at a time so really cant help with answers - just an opinion.
Its a long time for colossus to be alone and think its a nice idea to get company for them long hours.
The only true way to know if it will help keep Colossus company for the days would be to speak to the rescue centre. Make an enquiry and ask to meet Bubba 1:1 and then if you are more encouraged about having the 2 bullys together ask to arrange if possible Colossus meeting bubba and see how they get along.
Just suggestin this so you dont end up with 2 bullys that dont get along and ur plan for long term company for each other backfires. You wont know if Bubba is the right bully to join your family unless you make an enquiry and visit to help make your mind up - you can still say no afterwards x