"The James/Sharp" is the jacket name / trouser name as mentioned above. "The James1/Sharp3" vs "The James/Sharp" shows a first revision of the specs in the jacket against the original and the third revision of specs on the trousers against the original. They don't necessarily mean tighter/shorter but it's generally the case. This translates to any jacket/trouser combination.
In Boss all jackets currently fit under one of four overall "shades":
Comfort fit: Pasolini/Movie, Edison/Power, etc (jacket name starts with P or E)
Regular fit: The James/Sharp, The Keys/Shaft, etc (jacket is named "The" anything)
Slim fit: Huge/Genius, Darrington/Knight (jacket name starts with H or D or N)
Extra slim fit: Ryan/Win (jacket name starts with R)
Tailored line replaced Boss Selection and is half canvas with their own jacket/trouser names. I've seen older jackets like Rossellini and Scorcese for sale on ebay but know that these pieces are ancient and haven't seen production in years. Worse still is any jacket named after a scientist (Einstein or da Vinci, for instance) as they are an even bigger cut that comfort called classic and are giant, outdated, and are 100% old (mid 2000s or earlier). ebay buyers beware...
As for Pasolini vs Paolini, one is for normal production, one is outlet specific. The other outlet specific jackets are The Grand, Halsey, and Inwood. Quality is the same, they just skimped on some of the embellishments like pen pockets, etc.