Ok. I think I know what's with Big D. They don't want players to go too far by getting both guys weapons cap to 7. so your first guy can lvl all your weapons to 7. But Big D doesn't want people to prepare by having the second guy able top go to 7 on weapons so they made the second cap to 5. Heres a table...
1st
Cannon-7
sailing-7
Cutlass-7
Pistol-7
Doll-7
Second guy only gets those to 5...
I also think they give little special features for basic people. Because I lvld my first guys weapons long ago and was able to get the stronger versions of weapons. Now they don't let us get them. But we can start right up without having to wait.