In terms of teamplay, Bobb combines much better with his teammates and creates more chances. Savinho only has one way: dribble. Bobb is more versatile. Stops play, pass at first touch, plays through balls, makes right decisions, dribble in tight spaces...
The unique thing Savinho is over Bobb is pace. Even in defence Bobb helps more.
Probably Savinho is not a bad player but he doesn't fit in positional play.
Bobb's main problem is unconsistency, but Savinho lacks too.
Both can develop a lot. It's up to Pep to choose the right player for the right game.